Adhesives Pty Ltd v Aktieselskabet Dansk Gaerings-Industri

[1935] HCA 83

55 CLR 499

ADHESIVES PROPRIETARY LIMITED

AKTIESELSKABET DANSK GAERINGS-

RESPONDENTS.

INDUSTRI AND ANOTHER

RESPONDENTS, Patent-Improved process of manufacture-Subject matter-Specification-Sufficie

-Ambiguity-Misrepresentation.

Letters patent were granted to A in respect of improvements in the manu- facture of yeast." In A's specification the two theretofore-known methods of propagation of yeast were referred to. One method was to SOW seed yeast Feb. in a mash " of malted cereals. In the other, called the "air-grown method, a "wort " was obtained from the mash by filtration and the seed yeast sown in that; and the wort was diluted from time to time by further washings" obtained from the mash by filtration. A defect in both these processes was that the yeast developed under unfavourable conditions: the mash or wort became during fermentation poorer in nutrient substance owing to the con- sumption of substance by the propagation of the yeast, and the formation of alcohol retarded the propagation of yeast. In the air-grown method, aeration and dilution of the wort reduced the proportion of alcohol, but, as pointed out in A's specification, the result was that " the alcohol produced will be lost, as it will not be feasible, in practice, to recover the alcohol when diluted beyond a certain limit." Under A's process the yeast was to be sown in a diluted wort or mash, and then the process was to be controlled SO that the consumption of nutrients caused by the growth of yeast was balanced by the addition of stronger nutrients to the wort or mash. A claimed "a process for the manu- facture of yeast tration suitable for the formation of yeast is maintained in the wort or mash during the run of the fermentation, while by the addition of the necessary quantities or wort or mash of higher concentration, any variations in the concentration of the nutritive liquid due to the general vital activity of the yeast are equalized or compensated, whereby alcohol is formed in considerable quantities, which alcohol is either recovered or assimilated by the yeast, but only during the subsequent period of fermentation." The specification stated

55 CLR 500

that the process gave "a quite appreciable formation of alcohol, SO that the alcohol may either be caused to disappear again slowly during the process, or may be caused to remain, wholly or partially, as desired " and allowed the manufacture to be adjusted according to the varying state of the market for yeast and alcohol; and that "uncommonly large " yields of yeast might be obtained by the process although "quite considerable quantities of alcohol may be present during the fermentation."

Held, by Evatt J. :------ 1 There was no foundation for an objection to the validity of the patent on the ground of want of subject matter. The process invoked a new principle and, although it might not appear logical and simple, it swept aside all previous notions. The principle was embodied in a new method of manufacture which made a great step in advance of previous knowledge and possessed very great utility.

2 The question whether "assimilation" was in truth the cause of the disappearance of the alcohol was unimportant. An error in theory, although carried into the very terms of a claim, does not vitiate a patent if otherwise valid, SO long as from a practical point of view the public concerned are fairly given possession of the invention. The process was not dependent upon the cause and for all practical purposes of the trade it was immaterial whether the reason for the disappearance of the alcohol was that it was acted upon by a catalytic agent or converted by an oxidising enzyme.

3 On a proper understanding of the invention and the specification, there was no insufficiency, and, in particular, there was none in not giving instructions as to the concentrations of wort favourable to yeast production, because the main purpose of the invention was to maintain the concentration throughout the process SO as to balance consumption of nutrient substance against the growing activities of the yeast colony, and the general direction applied though the degree of concentration maintained might be varied in different conditions.

4 The invention was not anticipated. 5 The objection that the specification was ambiguous failed upon an examination of its meaning.

Held, by the Full Court, affirming Evatt J. :-

1The process was a new method of manufacture and the invention possessed subject matter. 2The invention consisted in applying a new method or principle of pro- cedure to existing knowledge and practice of yeast production and there was no insufficiency in failing to specify matters necessary to the production of yeast but independent of the invention and involving choice and judgment by those skilled in the art as known and practised. 3The specification did not claim results which the invention would not 4It was not bad for ambiguity. 5The invention was new. 55 CLR 501

APPEAL from Evatt J.

Adhesives Pty. Ltd. presented a petition to the High Court under sec. 86 of the Patents Act 1903-1932, for the revocation of letters patent, No. 13,229, granted on 7th November 1919, to Aktieselskabet Dansk Gaerings-Industri, of Copenhagen, Denmark, in respect of an invention by one Soren Sak for "improvements in the manufacture of yeast." The petitioner stated that it was duly authorized by the Attorney-General for the Commonwealth to present the petition; that it was a company duly incorporated in the State of New South Wales, and engaged, inter alia, in the manufacture of yeast and yeast products; and that Aktieselskabet Dansk Gaerings-Industri was the registered proprietor of the letters patent which were and always had been invalid and of no effect. The grounds, other than ground 1, which was not proceeded with, set forth in the particulars of objection upon which the petition was based were, as amended, substantially as follows :-(2) The alleged invention was not novel at the date of the grant by reason of (a) prior publication, and (b) prior common general knowledge. The particulars of prior publication relied upon were in respect of three British patents granted in 1880, 1888 and 1904 respectively to William Robert Lake, William Phillips Thompson and Evariste Vignier respectively, the specifications of which had been available for inspection at the patent offices of New South Wales and Victoria shortly afterwards, and in the library of the Commonwealth Patent Office since 1905. (3) The alleged invention was not proper subject matter for a patent. (4) The alleged invention was not useful. (5) The specification did not particularly describe the nature of the alleged invention or the manner in which it was to be performed in that no instructions were given in respect to many matters referred

(6) The specification and claims of the alleged patent did not adequately define the extent of the monopoly sought to be protected. (7) The specification and claims did not give sufficient information to enable the public to ascertain the scope and ambit of the claims. (8) Claim 1, both by itself and as incorporated by reference to claims 2 and 3, was ambiguous in respect of the following expressions (a) in accordance with the so-called differential management of the fermentation," (b) "the necessary

55 CLR 502

A. quantities of wort or mash of higher concentration," (c) " whereby

alcohol is formed in considerable quantities," and (d) "but only during the subsequent period of the fermentation." (9) The patent was obtained by the false suggestion that the process described in the specification was a process whereby the amount of alcohol present at the end of the process might be controlled and varied and that the process thus allowed the manufacture to be adjusted according to the varying state of the market for yeast and alcohol these suggestions were wholly false and devoid of foundation. The complete specification was as follows :-

Improvements in the manufacture of yeast.' [Col. 1] We, Aktieselskabet Dansk Gaerings-Industri, manufacturers of yeast, of Snaregade 12, Copenhagen, Denmark, hereby declare this invention and the manner in which it is to be performed to be fully described and ascertained in and by the following statement :-

In known processes for the manufacture of yeast the yeast to be used for propagation is either sown into the total quantity of mash, as in the skim-yeast (Vienna-yeast) method, or, as in the air-grown yeast method, first into the first wort which is then, subsequently, during aeration, diluted by addition of washing water SO as to make a certain definite quantity of final wort wherein the fermentation is completed.

In both cases the yeast propagates in a mash or wort becoming, during the fermentation continuously poorer in nutritive substance, one of the reasons for this being the consumption of substance caused by the propagation of the yeast. In the air-grown yeast method the concentration of the nutritive liquid is reduced not solely on account of the consumption of substance due to the propagation of the yeast, but also on account of the nutritive solution being diluted by addition of washing water, which addition is continued during the entire washing process. [Col. 2] In the said methods the individual yeast generations will develop under very different con- ditions of life, their development commencing in a nutritive liquid of high concentration, i.e., in a surplus of nutritive substance, while the last generations will develop under unfavourable conditions of life, i.e., in a weaker nutritive solution, where they will be wanting nutritive substance. Furthermore, the alcohol formed during the

55 CLR 503

fermentation according to the above-mentioned methods of fermenta- tion will have a retarding effect on the formation of yeast. The retarding action of alcohol on the yeast formation is especially prominent in the skim-yeast (Vienna-yeast) method. In the air- grown yeast method, it has been attempted to remedy this drawback, viz., the alcohol's retardation of the formation of yeast, by selecting suitably weak solutions, in which the alcohol formed could not materially injure the propagation of yeast. This process, however, has for effect that the alcohol produced will be lost, as it will not be feasible, in practice, to recover the alcohol when diluted beyond a certain limit.

In spite of the attempts to remedy these drawbacks, there will always remain, by the said fermentation methods the main drawback that the yeast during its development [Col. 3] must always work in a wort or mash becoming constantly poorer in nutritive substance,

SO that the last generation will have to fight against conditions of life which become constantly more unfavourable.

The present invention has for its object that the yeast is given as far as possible, uniform and favourable conditions of life during the entire fermentation process without using other nutritive substances than those utilized in the heretofore-known fermentation process. This is possible when the usual nutritive substances (that is, for instance, mash and wort) are supplied to the yeast in an entirely different manner from that heretofore known. Experience has shown that the desired result is attained, if the yeast is sown in a diluted wort or mash suitable for the propagation of yeast, and if the concentration of the nutritive liquid is maintained by equaliza- tion or compensation of the consumption of substance, SO that the fermentation is directed in a manner which may be called differential.

In contradistinction to the heretofore followed practice, the process may be commenced for instance by sowing the yeast into the last or a mixture of the last and the last but one washing water (the term washing water being taken to mean the liquid flowing from the filtration plant), whereafter addition is made of the stronger washing waters obtained at the beginning of the filtration, and of the first wort, according to requirements in order that the concentration

55 CLR 504

may be maintained in spite of the consumption of substances occurring.

An extensive series of practical experiments have shown in the production of good bakery yeast with uncommonly large yield, according to the present process, that even quite considerable quantities of alcohol may be present during the fermentation, and the process should therefore be carried [out] not only in such manner that such quantities of alcohol are formed and are present during the fermentation but also SO that the alcohol is not utilized by the yeast until during the further run of the fermentation, the alcohol being utilized or assimilated. The principal object of the novel process for the production of yeast is to provide an easily obtainable approximate compensation or equalisation of the variations occurring, in consequence of the consumption of substance, in the concentration of the fermenting wort or mash. The object of the invention is, in other words, the management of the fermen-[Col.4] tation in a manner which may be called differential.

According to the present invention the concentrations during the fermentation are not only adjusted in such a manner that they become favourable to the propagation of yeast, but they are also at the same time adjusted in such a manner that they furthermore give a quite appreciable formation of alcohol, SO that the alcohol may either be caused to disappear again slowly during the process, or may be caused to remain, wholly or partially, as desired.

The process thus forms a kind of regulator for a formation and conversion of alcohol going on co-ordinarily with the attainment of high yields of the best yeast. By the present process there may be used per unit volume of the fermenting solution, quantities of mashing material corresponding at least to those used by the heretofore- known air-grown yeast method. This process consequently allows relatively smaller quantities of air to be used than in the known processes by which smaller quantities of mashing material, per unit volume of fermenting solution are used, and it will therefore be seen that the present process offers advantages in respect to increased capacity of the plants. The advantages attained by the process amply outweigh the costs of the increased supervision made necessary, especially at the start, when the process is introduced in a factory.

55 CLR 505

The yeast thus produced, while quite considerable quantities of alcohol are present, appears in quantities corresponding to a yield of about 60% or more and, besides, it possesses internal and external qualities of exceedingly high value.

First a mash of 15° Balling and composed in usual manner is filtered. The original wort and the first washing waters-a mixture whose concentration may vary between wide limits and whose specific gravity here may be assumed to be about 10° Balling are conveyed, in hot state, into a special receptacle, in which the mixture is heated once more to 70 to 75°C. The third washing water or a portion thereof, mixed with the last washing water in such a propor- tion that the strength of the mixture will be 1.5 to 2.5° Balling, is conveyed through the cooler to the fermenting vat where yeast is added, while the temperature is maintained at about 30°C. There- after aeration commences and then, after the lapse of 2 to 3 hours, the hot and more concentrated wort is added, preferably [Col. 5] continuously and during intense aeration and in such manner that the addition of the wort will take 10 to 11 hours. Hereafter, during decreased aeration, the entire wort is allowed to ferment for one or two hours more, and the separation of the yeast then commences. As the wort contains quite unusually large quantities of yeast, it will be preferable to let some water run with it into the centrifugal straining apparatus.

During a fermentation as carried out in the above example, alcohol will be produced in quantities which may amount to 20% or more of the raw material corresponding to the quantity of wort present in the fermentation vat.

In fermentations as those here referred to, the alcohol will be present or may be present in a concentration enabling it to be recovered commercially.

The addition of the usual nutritive salts may be performed in usual manner, for instance, during the fermentation, or even in the wort before the sterilization.

By a slight variation of the temperature the aeration or the manner in which the wort is added, the amount of alcohol present at the end of the process may be varied.

55 CLR 506

The present process thus allows the manufacture to be adjusted according to the varying state of the market for yeast and alcohol.

The process may be used for cultivation of yeast to be sown (seed yeast, mother yeast) according to the air-grown yeast method and according to the skim-yeast (Vienna-yeast) method.

It will frequently be advantageous to SOW a very liberal quantity of mother yeast or seed yeast, and experience has shown that it may be of advantage to use a quantity of seed yeast to upward of 60% of the entire quantity of mashing material used.

The mashing process is effected in usual manner, and the mashing material used is of ordinary kind and composition. There may be used for example a mash volume of 18,000 litres, produced from 1,200 kilos of maize, 1,350 kilos of barley, and 450 kilos of malt-culms, in total 3,000 of mashing material. (Larger or smaller quantities of molasses may also be used in connection with barley and malt- culms.) The barley used should preferably be in the shape of malt.

The processes of saccharization, acidulation and sterilization are conducted in ordinary manner. The saccharization takes place for two to three hours at about 65°C. The [Col. 6] acidulation process is preferably started at 55°C. and is carried out in known manner for fifteen to sixteen hours. The sterilization temperature is about 70°C.

The filtration may be directed in such a manner that the wort which leaves the filter without washing, the first wort or main wort, is mixed with such quantity of the first washing water that the resulting mixture amounts to 210 hectolitres of 7.1° Balling (undiluted wort corresponds to 10° Balling). These 210 hectolitres are set aside, temporarily, and are kept at a suitably high temperature, say about 70°, or a suitably low temperature, say about 10°C. in order to avoid infections. The filtering process is continued, while further washing is performed, SO as to produce, besides the above- mentioned mixture, a mixture consisting of 196 hectolitres, which is collected in the fermentation vat, and into which mixture the seed yeast is sown. To this wort in the fermentation vat, which is on 1.7° Balling, 10 kilos of sulphate of ammonia are added. Then 600

55 CLR 507

kilos of seed yeast, and aeration is carried out for 21/2 hours, at the rate of 700 cubic metres of air per hour.

For the following hour the quantity of air is increased to 1,800 cubic metres and, during the next 9 hours, 2,800 cubic metres of air are supplied per hour. Then the amount of air is reduced, for the next hour, to 1,400 cubic metres, and then during the next hour to 700 and then to 200 cubic metres per hour, which rate of aeration is maintained until the end of the fermentation. Two and a half hours after the fermentation has been started, addition is made of 10 kilos of sulphate of ammonia and 312 hours after the fermentation has been started, a methodical addition of first wort is commenced, at the rate of 1,850 litres per hour for 9 hours and then about 2,220 litres per hour for the next 2 hours. Besides the above-mentioned amounts of sulphate of ammonia, addition is made 31, 51, 61, 71, 812 and 912 hours after the commencement of the fermentation, of 10 litres of 25% ammonia water each time.

During the fermentation, a temperature of about 30°C. is main- tained as far as possible.

When the fermentation commences, the wort in the fermentation vat is on 1.7° Balling, at the end of the fermentation it is on 2.6° Balling which is mainly due to the influence exerted on the specific gravity of the wort by the large amount of yeast contained in the wort. After the yeast has been re- [Col. 7] moved by a centrifugal machine, the wort thus treated is on 1.1° Balling.

The run of the fermentation process is seen clearly and distinctly from the following table, in which the column farthest to the left indicates the time from 5.30 when the fermentation is initiated, until 9 p.m. when it is finished. At 1/2 a.m. the fermentation was started.

55 CLR 508

In the above table I indicated the volume of the nutritive liquid in the fermentation vat, i.e. the 196 hectolitres of wort plus the additions made at various periods. The total finishing volume ought to be 196 plus 210 equalling 406 hectolitres, but 406 minus 398 equalling 8 hectolitres of water have been blown away.

Column II. shows the amount of alcohol contained in the wort expressed in per cent by weight.

Column III. corresponds to the alcohol contents of the wort expressed in kilograms of pure alcohol.

Column IV. indicates-figured as dextrose-the quantities of sugar corresponding to the quantities of alcohol in column III. figured according to the equation :-

> 2C H5 OH 2CO Column v. shows the quantities of sugar (expressed in kilograms of dextrose) which have been added, at various hours, to the fermenting wort.

Column VI. is arrived at by comparing the figures in column IV. with the corresponding [Col. 8] figures in column V., and its figures indicate what percentage of the sugar added has been converted into alcohol at the hour concerned.

Having now fully described and ascertained our said invention and the manner in which it is to be performed, we declare that what we claim is:

1. Process for the manufacture of yeast, especially air-grown yeast, in which, in accordance with the so-called differential manage- ment of the fermentation, a nutritive substance concentration suit- able for the formation of yeast is maintained in the wort or mash during the run of the fermentation, while by the addition of the necessary quantities of wort or mash of higher concentration, any variations in the concentration of the nutritive liquid due to the general vital activity of the yeast are equalized or compensated, whereby alcohol is formed in considerable quantities, which alcohol is either recovered or assimilated by the yeast, but only during the subsequent period of the fermentation.

2. A process as claimed in claim 1, in which the said process is used in the cultivation of yeast to be sown (seed yeast, mother yeast).

55 CLR 509

3. A process as claimed in claims 1 and 2 in which seed of such quantity of yeast (seed yeast, mother yeast) is employed as corres- ponds to upward of 60% of the mashing material used.

4. A process for the manufacture of yeast substantially as described.'

Commercial yeast is an aggregate of a vast number of yeast cells. Yeast is a microscopic single cell organism, the scientific name of which is saccharomyces. There are many different kinds of this organism. The yeast cell lives in a fluid medium of suitable com- position for its growth it obtains its substance from the required materials in the solution the fluid medium in which the yeast grows must therefore contain in solution the various constituents that are necessary for the growth of the yeast, and these constituents must exist in the solution in forms in which they are capable of assimilation through the walls of the cell. The main nutritives required by the yeast cell are sugar and nitrogen in suitable chemical forms. Other things, such as phosphorus, are also essential but in smaller quantities. Some forms of sugar are not assimilated by some forms of yeast, but it can be assumed that the specification only refers to those forms which are suitable for the particular type of yeast. Besides utilizing sugar for the purpose of nutriment, the yeast cell also has the property, which is of great commercial value, of converting one molecule of sugar into two molecules of alcohol and two molecules of carbon dioxide, and in this way a given weight of sugar SO converted yields approximately half that weight of alcohol and half that weight of carbon dioxide. The alcohol which the yeast cell produces is, if present in the solution in sufficient quantities, inimical to the growth of the yeast cell. Increase of the yeast takes place by budding, that is to say, a small daughter cell appears on the surface of the mother cell and may ultimately become detached. In a normal yeast brew there are usually about eight successive generations. The rate of alcohol production and the rate of growth of the yeast are very variable quantities, and prior to Sak's patent it was generally accepted that the conditions which were favourable to a large yield of alcohol were not favourable for a large growth of yeast, and vice versa. Industrially, yeast is used principally in brewing, wine making, alcohol production, spirit distillery and

55 CLR 510

bread making. For the bread industry yeast is generally supplied in a form known as "pressed yeast." A cake of pressed yeast consists of myriads of yeast cells which have been first separated from the mother liquid, generally by centrifuging, and from the mass SO obtained further water is expressed by pressure. The pressed yeast thus manufactured still contains, chemically, about 72 per cent of water, most of which represents the fluid material within the cell. In yeast manufacture there are, broadly, two stages. In the first stage the object is to prepare a medium which will contain in solution the various ingredients necessary for the growth of the yeast. In the second stage of the process the prepared material is innoculated with specially selected and prepared yeast, called "seed yeast," and that stage of the manufacture aims at obtaining as much yeast as possible from the materials employed in the first stage. When the nutritive liquid in which the yeast was grown has become exhausted, or practically exhausted, the process is brought to a close by the separation of the yeast cells from the liquid in which they have been caused to grow. The meaning of various technical terms used herein is as follows Mash."-The - grains, or whatever other vegetable materials are used for providing the necessary sugar, after being crushed, are mixed with water, and the mass is suitably treated for the purpose of extracting the desired ingredients. The whole mass thus treated is called the "mash." "Wort" is the liquid filtered off from the mash. "Vienna yeast " is yeast grown in the mash itself. "Air-grown yeast" is yeast grown in a wort through which air is caused to bubble from air pipes at the bottom of the tun. "Seed yeast " is yeast used for innoculating the commercial brews. It is specially prepared from a single selected cell, or several selected cells, which is or are propagated under special conditions designed to ensure particularly that the whole batch of seed yeast will be of suitable type and quality and as free as possible from foreign contaminating organisms. "Malt culms." -When a cereal grain, such as a wheat seed or barley seed, is exposed to moisture it begins to sprout; when this occurs, substances, called enzymes, within the grain proceed to act upon the starch and proteins stored up in the grain and to convert them, as far as starch is concerned, into sugar, and as far as the proteins are

55 CLR 511

concerned, into more easily available nitrogenous materials for the purposes of the young plant. When the sprout is about an inch long the germination is stopped by heat and drying, and the small sprouts are called "malt culms." "Balling" is a measure of density used in the fermentation industry. 1° Balling is the density of a solution of one part by weight of sugar in 100 parts by weight of water; 2° Balling is the density of 2 parts by weight of sugar in 100 parts by weight of water, and SO on. "pH."-This is a symbol used for indicating the hydrogen-ion concentration of a liquid. The hydrogen-ion concentration of a liquid refers to the quantity of free hydrogen ions in that liquid at a given moment, and according to such concentration it is either neutral or acid or alkali. pH7 represents the concentration when the liquid is neutral; pH values below 7 are acid and those above 7 are alkaline. Acidity is measured in two ways, namely, total acidity and pH acidity. The same applies to alkalinity. The total acidity of a given quantity of a given substance is measured by what is called titration, that is to say, by the quantity of standard alkali that it will neutralize. Titratable acidity is therefore the total available acidity. But some acids or acid substances operate much more slowly than others according to the differences in their hydrogen-ion concentration in the particular solution, and it is this difference that is indicated by the pH value, SO that two solutions may have the same titratable acidity, but different pH values, and vice versa.

The respondents to the petition were Aktieselskabet Dansk Gaerings-Industri Ltd., and Mauri Brothers &Thompson Ltd., a licensee under the patent.

The petition was heard by Evatt J., who, by consent of the parties, appointed Dr. R. K. Murphy and Dr. v. M. Trikojus to carry out certain experiments and to furnish a report thereon, and also as assessors to assist his Honour. The parties also consented to his Honour consulting the assessors out of court, and also having recourse to text books and scientific works on the subject.

Further material facts appear in the judgments hereunder. Bonney K.C. and Gain, for the petitioner. Flannery K.C. and W. J. v. Windeyer, for the respondents.

55 CLR 512

EVATT J. delivered the following written judgment :- This is a petition for the revocation of letters patent No. 13,229. It describes itself as being for "Improvements in the manufacture of yeast." The date of the application and complete specification was November 7th, 1919.

The grounds of objection as set out in the particulars have been slightly amended by (1) the abandonment of ground 1 (that the person named as actual inventor-one Soren Sak-was not the actual inventor), and (2) the abandonment by the petitioner of (a) Levy, (b) Claudon and Vigreaux, and (c) Kamienski, three prior publications referred to in particular 2 as (I.), (II.) and (IV.) respec- tively.

Meaning of Specification. The first question to be considered is the meaning of the complete specification, for upon that necessarily depends the force of many objections which have been taken. The specification states at the outset that in both the skim-yeast, i.e., the Vienna yeast process, and in the aerated process, of yeast manufacture, the yeast propa- gates in a mash or wort which becomes continuously poorer in nutritive substance during fermentation. The result is, it is asserted, that there is a growth of yeast "under very different conditions of life," the first generations developing in a nutritive liquid of high concentration, while ' the last generations" have to encounter 'unfavourable conditions of life."

Some argument was directed to the question whether the specifica- tion intends to limit the reference "unfavourable conditions' to the last generation of all; but it is clear from col. 2 that it does not SO intend and that it is intended to assert that in the latter end of the processes previously employed there is no longer a sufficiency of nutritive substances.

The specification next points out that in the two methods of manufacture usually employed, the alcohol formed during fermen- tation retards the formation of yeast. There has been an attempt to overcome this factor in the air-grown yeast method, by selecting suitably weak solutions of wort in order to prevent alcohol from being formed in quantities sufficient to retard the propagation of yeast. "This process, however," the specifier says, "has for effect

55 CLR 513

that the alcohol produced will be lost as it will not be feasible in practice to recover the alcohol when diluted beyond a certain limit."

When he comes to the end of the second column, the specifier has completed his preliminary statement of the problem. His basic declaration is that both the Vienna yeast method and the aeration method, as known and employed in 1919 in the Commonwealth of Australia, present practical difficulties to the manufacturer. In the first place, yeast propagation itself is unsatisfactory because an adequate concentration of nutritive substance is not maintained during the process, but, secondly, whereas the alcohol formed in strong-brew fermentation processes detracts from the successful production of yeast, the existing method in air-grown yeast produc- tion of using very weak brews, whilst certainly preventing enough alcohol from being produced to injure yeast production, is wasteful, because the alcohol produced has, for all practical purposes, to be treated as irrecoverable.

What, then, are the stated purposes of the present invention ? (I.) Its first and main purpose is clearly stated. It is to improve the manufacture of yeast SO as to obtain high yields. And the method or process adopted for achieving such an end is to secure

as far as possible uniform and favourable conditions of life during the entire fermentation." The process is to operate by sowing the yeast in a diluted wort and then maintaining the concentration of the nutritive liquid, having regard to the gradual consumption of nutritive substance by the growing yeast colonies. The essence of the method is that " the concentration may be maintained in spite of the consumption of substances occurring" " (col. 3). Thus the inventor provides an "easily obtainable approximate compensation or equalization of the variations occurring, in consequence of the consumption of substance, in the concentration of the fermenting wort or mash " (col. 3).

This method of compensating for loss of nutritive substance throughout the whole process of fermentation is illustrated by the suggestion that the yeast should be sown, not into the strong wort, but into the last washing water, or a mixture of the last and the last but one, and that, subsequently, additions should be made from

55 CLR 514

A. a reservoir, consisting of the first wort and the stronger washing

water (col. 3).

The specifier describes his method as the application of the usual nutritive substances (that is, for instance, mash and wort) in such a manner that the management of the fermentation may be called 'differential." This word vividly describes the outstanding feature of the invention. Under the new process, yeast is to be sown in a diluted wort or mash suitable for propagation, and then the process is to be controlled SO that the consumption of nutrient substances caused by the propagation and growth of yeast is balanced, and no more than balanced, by adding a sufficient supply of stronger nutrient to the liquid in which the yeast is propagating. The word " differen- tial" implies a balancing of one rate of change against others. Sak's method of controlling the process is quite analogous-as is suggested -to the difficulty presented, not SO much in solving a differential equation as to the preliminary and greater difficulty involved in writing it down. He claims that a certain relation exists in which the element of time (the fermentation process takes many hours) becomes all-important. In this way, he emphasizes, not only by his use of the term 'differential," but throughout the specification and by his particular examples and directions, that he is concerned with the adjustment of yeast growth (at a certain rate), consumption of nutrient substances as a result of such growth, and the furnishing of additional nutrient substances at such a rate as will compensate for the consumption of substances, having regard to the rate at which they are consumed. It is not merely a question of adding additional nutritive substances in a haphazard or unordered way, but of adding them in a particular way SO as to compensate for consumption losses.

(II.) The inventor also states that an incidental but important result may also be obtained from his process. He mentions at an early stage of the specification that the problem of alcohol recovery has also to be attacked. He asserts that "uncommonly large yields" of yeast have been obtained from his process, although "quite considerable quantities of alcohol may be present during the fermentation" (col. 3). He suggests that his process 'should" be carried out, " not only in such manner that large quantities of

55 CLR 515

alcohol are formed and are present during the fermentation, but also

SO that the alcohol is not utilised by the yeast until during the further run of the fermentation, the alcohol being utilised or assimilated' (col. 3).

This aspect of alcohol formation is again stressed when the specifier says that the concentrations

are not only adjusted in such a manner that they become favourable to the propagation of yeast, but they are also at the same time adjusted in such a manner that they furthermore give a quite appreciable formation of alcohol

SO that the alcohol may either be caused to disappear again slowly during the process, or may be caused to remain, wholly or partially, as desired" (col. 4).

These two references, when considered together, require the interpretation that "even quite considerable" or "quite appre- ciable' amounts of alcohol will be produced at some stage of the process. In other words, although yeast is the principal product with which the manufacturer is concerned, the process will or may be carried out in order that there will be alcohol production to the extent indicated. According to the inventor, the manufacturer, if he desired to obtain yeast only, may complete the process SO that the alcohol will disappear. But he also possesses the alternative of regulating the process SO as to capture the alcohol produced in the course of yeast manufacture.

The inventor sums up the features of his process by declaring that it "forms a kind of regulator for a formation and conversion of alcohol going on co-ordinarily with the attainment of high yields of the best yeast" (col. 4). This statement emphases the point elsewhere made that, although high yields of the best yeast are obtained, there has been in the process formation of alcohol to an appreciable or substantial extent, which alcohol in the normal operation of the process will be converted SO as to be utilised or assimilated by the yeast; but the statement is also in direct line with the earlier representation and promise that the alcohol SO formed may, if SO desired, be retained and captured by the yeast manufac- turer at the end of the process.

Mr. Bonney argued that the express mention that under the old process you lost the alcohol if you sought to avoid retardation,

55 CLR 516

clearly leads one to expect that under Sak's process, you can get the yeast without losing the alcohol."

This argument is based upon the statements in col. 2, where it is said that the retarding action of alcohol on the yeast formation is especially prominent in the skim-yeast (Vienna yeast) method. In the air-grown yeast method, it has been attempted to remedy this drawback, viz., the alcohol's retardation of the formation of yeast, by selecting suitably weak solutions, in which the alcohol formed could not materially injure the propagation of yeast. This process, however, has for effect that the alcohol produced will be lost, as it will not be feasible, in practice, to recover the alcohol when diluted beyond a certain limit."

The meaning of this statement is that, in the aerated method of yeast manufacture, such weak solutions are employed that, although yeast growth is not detrimentally affected, such alcohol as is produced will be irrecoverable. But this does not mean that the Sak process promises that, at the end of his process, there will be (1) a maximum production of yeast, and (2) at the same time the production and capture of alcohol in commercial quantities. The statement in the specification means that, instead of "suitably weak" solutions, stronger solutions may be used, SO that (1) the alcohol produced will not be negligible but considerable, and (2) if, having regard to the state of the market (col. 5), it is desired that the alcohol produced in the process should be retained, that may be done.

It was also argued that the process promises a yield of yeast of about 60 per cent or more," together with alcohol in considerable and recoverable quantities if desired. I am quite satisfied, having regard to the whole of the evidence and the authorities, and to the information afforded to me by the expert assessors, that the specifica- tion is not to be SO construed.

The reference in col. 4 is that 'the yeast thus produced, while quite considerable quantities of alcohol are present, appears in quantities corresponding to a yield of about 60 per cent or more." This means that the process, when carried out to its normal con- clusion (i.e., in the maximal production of yeast), SO that there is no desire to obtain alcohol at the end of the process, will give the percentage mentioned. It is obvious from the scientific facts that,

55 CLR 517

where little or no alcohol is produced, a higher percentage of yeast is obtainable than where a substantial or considerable production of alcohol has to be obtained. Therefore the objector has to maintain that the "about 60 per cent or more" is a reference to the minimum production of yeast. In my opinion it is a reference to the out- standing feature of the invention-that yeast production under the process may reach the previously unheard-of percentage of " about 60 per cent or more" notwithstanding the fact that, in the course of the process, "quite considerable" quantities of alcohol have been produced. Such an assertion was quite revolutionary, having regard to the state of the art. It is unreasonable to suppose that a scientific impossibility was also being suggested.

In the specification, two examples of the process are furnished. Example I. indicates that yeast is added to washing water of a strength of 1.5 to 2.5 degrees Balling, while the stronger mixture at 10 degrees Balling is set aside in a special receptacle SO as to be added at later stages to the weaker mixture. After two or three hours' aeration, the more concentrated wort is added "preferably continuously' during intense aeration over a period of ten to eleven hours. The process is described, and it is said there will be produced "quite unusually large quantities of yeast" (col. 5).

I regard example I. as concluding at line 10 of col. 5, because in line 12 the specifier refers to " the above example."

It is asserted that, during a fermentation carried out in accordance with example I., alcohol will be produced in quantities which may amount to 20 per cent or more of the raw material corresponding to the quantity of wort present in the fermentation vat " (col. 5). He also says that in fermentations as those here referred to, the alcohol will be present or may be present in a concentration enabling it to be recovered commercially ' " (col. 5).

In my opinion, this reference to the quantity of alcohol which will or may be produced explains the other references in the specifica- tion to "quite considerable quantities of alcohol" and "quite appreciable formation of alcohol." A dispute arises as to what the 20 per cent is intended to refer to, whether it invites a comparison with the original raw material itself or with the dextrose derived from such raw material and SO represented in the fermentation vat,

55 CLR 518

or with some other standard of comparison. The question is

referred to elsewhere. The further statement that alcohol " will be present or may be present in a sufficient concentration to permit of commercial recovery, is no more than a repetition of the earlier statement that, if it is desired to capture alcohol, the process may be side-tracked for that purpose, whilst yeast production will also ensue.

In my opinion, the reference to alcohol recovery does not mean that the inventor suggests that at any given time or place, or at any time, such recovery " commercially' will necessarily be economically profitable. All he says is that the concentration of alcohol will be sufficient to permit of recovery for commercial purposes. The concentration he points to is, I think, that already indicated, viz., a concentration which may have amounted 'to 20% or more " at some stage of the process.

The outstanding clue to the relation between alcohol and yeast production under the process is to be found in the statement that " the present process thus allows the manufacture to be adjusted according to the varying state of the market for yeast and alcohol" (col. 5). This clearly implies that the process should not be regarded as giving at one and the same time the maximum production both of yeast and alcohol. In the sentence quoted the reverse is plainly indicated. If it is unprofitable to use the process for alcohol recovery, such recovery should not be attempted, notwithstanding the fact that alcohol is being produced in sufficient quantities to allow of recovery in commercial quantities. If, however, in relation to alcohol the yeast market becomes relatively unprofitable, the process can be used SO as also to produce both alcohol and yeast, the latter in lesser quantities than otherwise.

Example II. differs from example I. in that the wort into which the yeast is sown is at 1.7 degrees Balling, and the stronger wort which is set aside for future service of the yeast is at 7.1 degrees Balling. It is unnecessary to refer to example II. in detail, but it shows clearly in col. III. of the table that at a comparatively early stage of the process the amount of alcohol contained in the wort amounts to 87 kilogrammes of pure alcohol, and that, as the process goes on, this quantity decreases, until at the end, only 4 kilogrammes are present. Example II. may therefore be regarded as a case

55 CLR 519

within the specification where "considerable" or "appreciable' quantities of alcohol have been produced, but have subsequently disappeared, presumably either by assimilation on the part of the yeast, or utilization in some other way.

There is also a discrepancy in example II. between the table in col. 7 and the reference to three and a half hours in col. 6. This discrepancy is unimportant because it is generally agreed that the text should yield to the table, and, in any event, substantially the same ultimate results are obtained if the text itself is followed.

The claims are all summed up or built upon claim 1. Firstly, it claims a process for yeast manufacture in which in accordance with the so-called differential management of the fermentation, a nutritive substance concentration suitable for the formation of yeast is maintained in the wort or mash during the run of the fer- mentation, while, by the addition of the necessary quantities of wort or mash of higher concentration, any variations in the concentration of the nutritive liquid due to the general vital activity of the yeast are equalized or compensated" (col. 8).

Particulars 6, 7 and 8-Ambiguity. This part of the claim is said to contain ambiguities. In my opinion, the contention is not made out. The differential manage- ment " is adequately and sufficiently described in several places of the specification, both in general terms and by particular instances. Emphasis is also laid upon the uncertain meaning of the " necessary" quantities of more concentrated wort. But the application of the phrase is not uncertain, because it refers to such quantities of more concentrated wort as will from time to time balance the loss of the nutritive substances owing to the demands of the ever-increasing colony of yeast cells.

Secondly, having described the differential process accurately in claim 1, the specifier then goes on to limit his claim to such a use of the process as will result in the formation of alcohol " in considerable quantities." It is also suggested that this is an ambiguous reference. Having regard to the indications elsewhere given in the specification, the specifier has already, as I have pointed out, indicated what he means by "considerable" formations of alcohol. It is such a

55 CLR 520

quantity as will be sufficiently concentrated to permit of commercial recovery, there being a further indication in the figure "20% or more as to what precise quantity is regarded as satisfying this description to the maximum extent.

The third part of claim 1 contains a limitation by way of the further description that the alcohol formed to the extent indicated is either recovered or assimilated by the yeast, but only during the subsequent period of the fermentation." It is also said that this period is not precisely ascertained. In my opinion, it is clear that the claim, read in the light of the specification, indicates definitely that, alcohol having been formed to the extent mentioned, the process is not then terminated but continued for such a time as is indicated for instance in the table of example II., where it is stated that " the run of the fermentation process is seen clearly and distinctly from the following table" (col. 7). The table indicates that, at 10 a.m., the process will have resulted in the production of 87 kilogrammes of pure alcohol. It also indicates that thereafter the process is continued for a period of eleven hours. This is made sufficiently plain elsewhere. Example I., for instance, states that the hot and more concentrated wort is added over a period of ten to eleven hours (cols. 4, 5). The "subsequent period" referred to in claim 1, therefore, means such a period as will enable the alcohol to be "recovered" or "assimilated by the yeast."

Particular 8 of the objections to claim 1 on the ground of ambiguity is therefore not sustained. With ground 8 there may also be con- sidered grounds 6 and 7. Ground 6 is that the specification and claims do not adequately define the extent of the monopoly, and ground 7 that they do not give sufficient information to enable the public to ascertain the scope and ambit of the claims. In my view, the analysis both of the specification and of claim 1 which has been attempted, shows that the monopoly claimed is sufficiently defined

SO that persons reasonably conversant with the trade and art in 1919 would understand the area which is forbidden.

One difficulty which is said to be contained in claim 1 is the assertion that the alcohol produced, if its recovery is not sought by the manufacturer, will be "assimilated" by the yeast. No specific

55 CLR 521

objection is raised in the particulars that the asserted fact of assimila- tion of alcohol cannot be proved or known.

On the hearing, some evidence was directed to this question. deal with the matter elsewhere, but I do not think that any specific finding upon it is actually required. Those to whom the specification was addressed could not fail to know that the process described in claim 1 was not intended to be, nor was it, in any way dependent upon whether the alcohol produced in the process, but not sought to be recovered, was assimilated" by the yeast, or whether it was, as suggested in the specification, "utilized" by the yeast (col. 3). For all the practical purposes of the trade, it was immaterial whether the alcohol produced and stated to have subsequently disappeared from the vat, was acted upon by a catalytic agent, or was converted by an oxidising enzyme associated with the yeast into some of its simpler oxidation products with a consequent gain of energy to the yeast. In the circumstances, the assertion of the fact of actual assimilation was only of theoretical and of no practical importance in enabling the public concerned to ascertain the territory covered by the claims. "Assimilation" became, for all practical purposes, at once the antithesis of commercial recoverability, and the synonym for commercial irrecoverability, of alcohol.

This question of erroneous statement of theory is referred to in " " " " " Electric Lamp Manufacturing Co. v. Marples Leach &Co. 1, where it was shown from knowledge gained after the date of the patent that the process of treating carbon filaments with certain phosphorous compounds did not remove all traces of carbon from the filament. But the specification had asserted that the process removed even the last traces of carbon in the filament."

Fletcher Moulton L.J. said that the specification might justly be criticised from the point of view of abstract accuracy. He said that

" carbon, as injurious carbon, is removed by the invention. Carbon from the chemical point of view is not removed. A lamp-maker at the date of the grant would naturally imagine that the whole of the carbon had been removed, because the deleterious consequences of the presence of carbon no longer existed, and that was the only way in which he was aware of the presence carbon. That being so, I think that the erroneous view, from a chemical standpoint, was one into which a lamp-maker might naturally fall, and that it would not in the slightest degree diminish the completeness of the disclosure

1(1910) 27 R.P.C. 737. 55 CLR 522

to the public of the invention, how to apply it, and what its practical conse- quences would be. Consequently I hold that, according to the English patent law, such an error is unimportant. The patentee's obligation is not to be omniscient the patentee's obligation is to put the public in the possession of his invention, and if he does that bona fide, in such a way that they know its advantages practically, and they can obtain those advantages practically, the fact that he has formed an erroneous view in theory of that which procures those advantages, or the state of things in which those advantages occur, does not, in my opinion, militate against him ,, 1. This decision is important because the actual claim was In the manufacture of incandescent electric lamp filaments free from carbon, the employment" of the phosphorous compounds to act on the raw filaments. In other words, the erroneous statement as to the complete expulsion of carbon from the filament was carried into the claim itself. In point of fact, the error was not known at the time of the patent, but was only ascertained subsequently. But the judgment holds that, although the error existed or was known to exist, even at the date of the patent, and although the error was carried into the very terms of the claim, this did not vitiate the patent if otherwise valid, SO long as from a practical point of view the public concerned were fairly given possession of the invention.

Apart from the question specially referred to above, I see no difficulty in the definition of the monopoly found in the claim. On the contrary, I regard the description in claim 1, before alcohol is mentioned at all, as a very clear description of the differential process. It could hardly be bettered, because it explains what is enough to indicate to the trade the territory which is forbidden, and yet it does SO in a sufficiently general way to render difficult the task of the proposing infringer.

In the case of Watson, Laidlaw &Co. Ltd. v. Pott, Cassels and Wib liamson 2 Lord Shaw said :-

"A patentee must not use language SO vague as to enable him to secure a monopoly for more than his real invention, and so to invade the rights of free rivals. But, on the other hand, it is permissible to state the real invention in language of such generality as is essential to preserve it and to prevent those rivals from invading the rights of the patentee. In the present case, I think that the specification and claim complied with these principles and that the vagueness is not deceptive vagueness

but is only that generality which would secure (to the inventor) the substance of his idea. In the case

1(1910) 27 R.P.C., at p. 746. 2(1911) 28 R.P.C. 565, 55 CLR 523

of Simpson v. Holliday 1

a distinctly alternative form was adopted by the patentee in his description of his invention. It was proved that one of the alternatives was an impossible or inoperative alternative. Nor can I leave out of view, in regard to the criticism directed against the vagueness this specification, that there is no evidence that any practical man, acquainted with that class of work, would fail, on account of the vagueness of language, to make a machine which would adopt and adapt the idea usefully and success- fully " 2. The reference to alcohol in claim 1 is, of course, a narrowing of the territory of the monopoly, and the question then becomes- reading claim 1 as a whole-whether the internal boundary brought into existence by the alcohol feature of the process is itself sufficiently defined. In my opinion, it is defined in such a way that a person in the trade-again I speak of 1919-would have it conveyed to him without obscurity that the process did not seek to avoid, but welcomed, the production of alcohol in recoverable quantities, SO as to enable the manufacturer to adapt the process, in order to (1) produce yeast only in maximum quantities and no alcohol, or (2) produce yeast in substantial quantities and also commercially recoverable quantities of alcohol. I, therefore, reject particulars of objections Nos. 6, 7 and 8.

Particular 5-Insufficiency. It is convenient now to turn to particular 5, which is directed to insufficiency of description and method of performance. Before considering the objections in order, I should refer to several of the leading cases.

As was pointed out by Jessel M.R. in Otto v. Linford 3, omissions in the description which would be obvious to the " skilled mechanic" " in carrying out an invention, and which he would be able to deal with without the exercise of invention itself, do not invalidate a patent. He said :-

'In these matters, therefore, it is not for us to find out how not to do it but the workman, when he finds that the drawing does not work exactly, sets himself at once to see how it ought to be done, and in practice, the thing

We have the usual evidence in this case. Engineers are called who say that a workman will find it out and put it right there is not produced on the other side a workman who said he had ever tried to make the machine and could not

A specification for improvements

1(1866) L.R. 1 H.L. 315. 2(1911) 28 R.P.C., at p. 580. 3(1882) 46 L.T. 35. 55 CLR 524

in gas motor engines is addressed to gas motor engine makers and workers, and not to the public outside" 1. In Goddard v. Lyon 2 the Lord Chanceller, Lord Herschell, said

"Although it may have been a matter of experiment as to how high it was desirable to go with regard to the pressure, yet from the outset, as I read the evidence, those who made use of this apparatus understood it to be an apparatus for the use of steam at a considerable pressure, and so employed it, and, according to the evidence, very advantageously employed it." In British Thomson-Houston Co. Ltd. v. Corona Lamp Works Ltd. 3, where the claim was for "an incandescent electric lamp having a filament of tungsten or other refractory metal of large diameter or cross-section, etc.," the argument was that, as "large" was a relative term, its inclusion both in the description and in the claim vitiated the patent. Lord Haldane said :-

"I do not think that in the specification before us it was intended to define, or that it is possible or necessary to define, the expression 'large' as referring to any definite limits. All that was necessary was lamp-makers how to get as large an incandescent surface as they wanted for their particular purposes. He made plain to them in the specification that this was no longer impracticable, and that, if they would adopt his new process of manufacture, they would attain a valuable commercial result, the outcome of the scientific principle implied in the process" 4. He added :-

" "Patents for a new discovery which is of SO far-reaching a character that its nature and principle can be conveyed in the shape of a specific set of instruc- tions to manufacturers, are not very common, but there are well-known examples of them which illustrate how little in the case of a really pioneer invention the description of the means of giving effect to it need be expressed separately from that of the principle discovered. The new process of manufac- ture may be of SO general a character that it can be carried out by numerous mechanical equivalents, none of which in themselves require further invention, but which will suggest themselves to practical men skilled in the subject " 5. Lord Haldane further stated :-

55 CLR 577

mash. No evidence to the contrary has been discovered. But, in any event, the expression 20% or more of the raw material corresponding to the quantity of wort present in the fermentation vat," while obscure, does not seem to refer to the initial quantity of raw material. It seems to refer rather to an amount of raw material still represented in the wort. The form of expression describes a correspondence between the wort present when the quantity of alcohol is calculated and the raw material. There is a good deal to be said for interpreting the phrase as expressing the alcohol content attained by the wort in the progress of the fermentation by the fourth of the five methods which Evatt J. has said are available for the expression of alcohol yields, viz., a percentage based on the total soluble materials in the wort which has been obtained from the mashing process. But however that may be, the specification does not upon its true interpretation contain the representation relied upon by the appellant. Upon this subject it may be remarked that the present attempt to fix upon this specification a representation or undertaking which could not be fulfilled by the invention is open to the well-known observations about the construction of claims which Sir George Jessel M.R. made in Plimpton v. Spiller 1 :- " There are few patents of complicated inventions even as regards the text and drawings where some mistake or other is not made. Accuracy, as we all know, is very difficult of attainment; and when the judge sees that there is a real substantial invention of great merit, and the description is fairly made, SO that a competent work- man can make the invention, it is not his duty to endeavour to construe the patent SO as to make it claim that which it is utterly absurd to suppose would be claimed, because it is SO well known as a matter of public notoriety, that nobody would think of claiming such a thing."

In dealing with this case I have not gone over in detail all the subsidiary arguments advanced in support of the grounds of attack. In many instances they were inconsistent with the view of the specification I have expressed, and in the course of stating that view I have disposed of them. But in any case very few of them

1(1877) 6 Ch. D. 412, at p. 423. 55 CLR 578

have escaped examination in the judgment appealed from, with the reasoning of which I entirely agree.

In my opinion the appeal should be dismissed with costs.

McTIERNAN J. At the hearing of the petition voluminous evidence was given as to the meaning of the technical terms and the state of knowledge in the art of yeast-making. Evatt J. had the assistance of two assessors, who by consent of both parties were appointed by the Court to carry out experiments founded on the directions con- tained in the specification and to furnish a report. Their elaborate report is in evidence. The parties also gave his Honour liberty to consult the assessors out of court in the absence of the parties and to inform his mind as to matters in issue by reference to text books. The report of the assessors is entirely favourable to the respondent. His Honour found as a fact that a person skilled in the art could by following the examples in the specification obtain substantially the yield of yeast promised, having regard to the amount of raw materials used. That yield was uncommonly large by contrast with the yield which could be obtained from a similar quantity of raw materials. His Honour found also that the quantity of alcohol which was formed during the experiments was substantially equivalent to that which the patentee promised, even according to the appellant's interpreta- tion of the specification. In SO far as the appellant's case depends upon these and other questions of fact I think it impossible to disturb his Honour's findings of fact, which were all adverse to the appellant. We lack not only the usual advantages which the primary judge had, to determine questions of fact, but the added advantages, consultation with the assessors and reference to text books which were available to him by the express consent of the parties (Mersey Docks and Harbour Board v. Procter 1; Federal Commissioner of Taxation v. Clarke 2 ).

The first objection to the validity of the patent which it is con- venient to consider is that claim 1 is ambiguous. No separate attack was made on the other claims. The claims should be inter- preted in the light of the body of the specification and the common

1(1923) A.C. 253, at pp. 258, 259. 2(1927) 40 C.L.R., at pp 292, 293 55 CLR 579

knowledge in the art.

The learned judge's summary of the specifica- tion was accepted as correct by the appellant's counsel.

The nutrients for yeast are sugar and nitrogen, which are derived from the mash or wort in which yeast is sown. Some of the raw materials from which mash or wort is made are richer in nitrogen than others and it is common knowledge that inorganic substance, e.g., ammonium sulphate, might be added to the mash or wort to increase the nitrogenous content. As fermentation proceeds the yeast splits the sugar or dextrose in the mash or wort into equal parts of alcohol and carbon dioxide. It was a matter of common knowledge how to measure the sugar concentration and the nitro- genous contents of the medium in which the yeast grows, and to gauge its acidity.

The specification gives a reasonably correct account of a defect which was characteristic of the two known processes, the "skim- yeast (Vienna-yeast) method' and the "air-grown yeast method." As to these processes it says :-" In both cases the yeast propa- gates in a mash or wort becoming, during the fermentation poorer in nutritive substance, one of the reasons for this being the consumption of substance caused by the propagation of the yeast." The specification says that when the air-grown method is employed the nutritive medium also deteriorates, "on account of the nutritive solution being diluted by the addition of washing water." This refers to the wort obtained from the mash by filtration. The yeast was sown in wort less dilute than the wort which was subsequently added. The defect in both of these processes, to which the specifica- tion draws attention, is that the yeast developed under unfavourable conditions of life and the formation of alcohol during a fermentation conducted according to either of these methods retarded the produc- tion of yeast. In the case of the skim-yeast method, the detrimental effect of alcohol to the production of yeast is stated to have been especially prominent. When the "air-grown yeast method" was used, an attempt was made to overcome this disadvantage by select- ing suitably weak solutions in which the alcohol formed could not materially injure the propagation of yeast. Commenting on this provision the specification says "This process, however, has for effect that the alcohol produced will be lost, as it will not

55 CLR 580

be feasible, in practice, to recover the alcohol when diluted beyond

a certain limit."

The object of the alleged invention as stated in the specifica- tion is to give "uniform and favorable conditions of life during the entire fermentation process without using other nutrient sub- stances than those utilized in the heretofore-known fermentation process." It is said that it is possible to provide these uniform and favourable conditions for the propagation of the yeast "when the usual nutritive substances (that is, for instance, mash and wort) are supplied in an entirely different manner from that heretofore known." The patentee discovered that, by the management of the fermentation in a manner which he calls " differential," uniform and favourable conditions of life are given to the yeast, resulting not only in an uncommonly large yield of yeast, but also in the formation of "considerable quantities" of alcohol. The manner of manufactur- ing yeast by the differential management of the fermentation is then described, and two examples of a fermentation conducted according to this method are given. The alleged invention is this manner of manufacture. The yeast is sown in a " diluted wort or mash suitable for the propagation of yeast " and " the concentration of the nutritive liquid is maintained by equalization or compensation of the consumption of substance." The method of maintaining the concentration, which constitutes part of the manner of manufacture, is explained in the following terms: "In contradistinction to the heretofore followed practice, the process may be commenced for instance by sowing the yeast into the last or a mixture of the last and the last but one washing water (the term washing water' being taken to mean the liquid flowing from the filtration plant), where- after addition is made of the stronger washing waters obtained at the beginning of the filtration, and of the first wort, according to requirements in order that the concentration may be maintained in spite of the consumption of substances occurring." The process is also illustrated by the two examples. Before this specification it was common practice to avoid forming alcohol during the fermenta- tion as it was regarded as detrimental to the propagation of yeast. Accordingly yeast-makers strove for a solution with the lowest degree of sugar concentration compatible with the growth of yeast,

55 CLR 581

thus avoiding comparatively the formation of alcohol. Thus alcohol would be formed only in negligible quantities. But the patentee, having discovered that the result of maintaining the con- centration of the nutritive substances was an uncommonly large yield of yeast and the formation of alcohol in considerable quantities, has made such formation an essential factor of the process. The specifica- tion says: " An extensive series of practical experiments have shown in the production of good bakery yeast with uncommonly large yield, according to the present process, that even quite considerable quan- tities of alcohol may be present during the fermentation, and the process should therefore be carried out not only in such manner that such quantities of alcohol are formed and are present during the fermentation but also SO that the alcohol is not utilized by the yeast until during the further run of the fermentation, the alcohol being utilized or assimilated." This factor in the process is again described in these terms "According to the present invention the concentrations during the fermentation are not only adjusted in such a manner that they become favourable to the propagation of yeast, but they are also at the same time adjusted in such a manner that they furthermore give a quite appreciable formation of alcohol, SO that the alcohol may either be caused to disappear again slowly during the process, or may be caused to remain, wholly or partially, as desired."

The further run of the fermentation is the last stage of the process: the first is a "lag" or dormant period and the intermediate stage is "the run of the fermentation." The alleged invention, therefore, consists of a manner of manufacturing yeast which is carried out by sowing the yeast in the more dilute of the filtrations of mash or wort and maintaining the concentration of the nutritive substances con- stant in such mash or wort, by adding, during the run of fermentation, the relatively less dilute filtrations of mash or wort, the concentra- tions of the sugar in the mash or wort being adjusted SO as to form considerable quantities of alcohol and to cause the alcohol to remain until the end of the process or in the alternative to be "utilized" or assimilated by the yeast.

In my opinion claim 1 defines with sufficient certainty the area of the monopoly granted for this process of making yeast. The

55 CLR 582

A. "differential management of the fermentation" is a phrase coined

by the specifier but its meaning is defined by the specification. The maintenance of a constant of nutritive substances in a mash or wort may require the addition of inorganic substances, that is, ammonium sulphate, to replenish it with nitrogen. But the characteristic of the invention is the maintenance of a constant concentration adjusted to form alcohol in considerable quantities, by adding, during the fermentation, wort of a higher concentration than that in which the yeast was sown. The skilled yeast-maker would know whether a practical constant was being maintained in the concentration of the nutritive substance. There were tests and instruments in common use for this purpose. If he maintained this constant by the addition of mash or wort of higher concentration" he would be within the ambit of the monopoly. The common practice having been to SOW the yeast in the less dilute filtrations of mash or wort, it is not doubtful, I think, that a practical yeast-maker would not fail to appreciate the meaning of the description "higher concentra- tion." The former processes strove to avoid the formation of alcohol, and the term "considerable quantities of alcohol" marks the con- trast between the results achieved by the present process and a mere negligible amount of alcohol. The term is explained by the specifica- tion and it indicates any volume of alcohol which may in a practical sense be described as "considerable" or "appreciable" or is capable of commercial recovery as distinct from recovery in a laboratory.

It is contended by the appellant that the question whether yeast may assimilate alcohol has not been scientifically determined, and that it would therefore be impossible for a manufacturer to know whether he was inside or outside the ambit of the monopoly if he managed the fermentation in a differential manner, adjusted the concentration to form alcohol as well as yeast, but caused the alcohol to disappear from the wash. The appellant has not, I think, dis- charged the onus of proving that alcohol may be made to disappear without being "assimilated" by the yeast. Reverting to the specification, it is noticed that "assimilated" is used as an altern- ative to the expression "utilized." Diverse opinions were expressed by the expert witnesses on this question, and Mr. Flannery referred

55 CLR 583

to an authority which tends to support the view that alcohol may be assimilated by yeast (Journal of Biological Chemistry, vol. 62, pp. 823-836). I do not think that this allegation of uncertainty in the definition of the monopoly has been established.

So far as regards the other objections, insufficiency, anticipation, want of subject matter, and the allegation that the patentee has promised results which it is impossible to achieve, I agree with the reasons of Evatt J. for dismissing these objections. On the question of subject matter, the judgment is supported by the decision in Hickton's Patent Syndicate v. Patents and Machine Improvements Co. Ltd. 1.

In my opinion the appeal should be dismissed.

Appeal dismissed with costs. Solicitors for the appellant, Allen, Allen &Hemsley. Solicitors for the respondents, W. A. Windeyer, Fawl &Windeyer.

1(1909) 26 R.P.C., at pp. 347, 348.