according to that patent, there is as little slag as possible, the object being to bring the metallic iron in a deoxidized state into immediate contact with the molten iron without a chance of its being reoxidized. That is very much the same thing as the respondent's claim.
It was suggested that the respondent's claim might be supported as a claim for a combination.
In the case of a combination it is no objection that all the elements are old, but there must be some- thing new. in the combination itself. The invention is the com- bination. On this point I will read a passage from Clark V. Adie 1. After speaking of the different ways in which a patent for a combination may be infringed, Lord Cairns L.C. said
But, my Lords, there is a third way in which it is possible to conceive an infringement of a patent of the kind to which I have referred. In a patent claiming an entire instrument made by a consecutive number of steps, there may at the same time be what
I will term, as perhaps the most convenient term I can think of, an invention which is a subordinate integer in the larger inven- tion. Inside the whole invention there may be that which itself is a minor invention, and which does not extend to the whole, but forms only a subordinate part or integer of the whole. Now, again, that subordinate integer may be a step, or a number of steps in the whole, which is or are perfectly new, or the subor- dinate integer may not consist of new steps, but may consist of a certain number of steps SO arranged as to form a novel com- bination within the meaning which is attached by the patent law to the term combination.' In that case you may have to try a further question you may have then to look at the patent, not merely as a patent for the whole instrument described, but as a patent which, in addition to claiming protection for the whole instrument SO made, claims protection also for the subordinate invention, the subordinate integer, which enters into the com- bination of the whole. Suppose, my Lords, that in a patent you have a patentee claiming protection for an invention consisting of the parts which I will designate as A, B, C and D; he may at the same time claim that as to one of those parts, D, it is itself a new thing, and that as to another of those parts, C, it is itself a
12 App. Cas., 315, at p. 320.