Case Comment

American Cyanamid Company v.
Ethicon Limited

citation(s): [1979] R.P.C. 215 (per Graham, J.)

copyright 1997 Donald M. Cameron, Aird & Berlis




The Decision

At p. 261

"What, then, are the requirements here? The directions in a specification must be sufficient to enable the notional instructed reader, armed with the knowledge and experience expected of a man skilled in the art, to make a fibre which falls within the words of the claim and which adequately fulfils any promise in the specification which it is stated or necessarily implied that any fibre falling within the claims will meet. A patentee is not under any obligation to make promises in respect of the articles which he claims, but, if he does so and if it is fair as a matter of construction to treat the promise as material and as coterminous with a relevant area covered by the claims, then it seems to me a product falling within that area must be tested by that promise when considering whether there is present insufficiency, inutility or false suggestion."

At p. 245-246

"These difficulties arise because the art of polymer chemistry is not an exact science and because a specification such as the present cannot, in my judgment, be regarded as being addressed solely to a professor of chemistry deemed to think, primarily at any rate, in terms of the precise classification of the structural formulae of organic compounds. It should rather be considered as being addressed to a body of technical men pooling their knowledge and working together in the employment of, or under the general direction of, a company engaged in research and production of artificial sutures. This body would be likely, in fact, to include, and for present purposes should, in my judgment, be deemed to include, at least one or more of each of the following classes of persons: polymer chemists, polymer fibre technologists and biomedical technologists in the company's research and testing department, and production chemists and controllers engaged in these, or closely analogous, manufacturing operations. In cases where specialised knowledge is required for understanding and working out the instructions of a technical specification, particularly one relating to a novel art or field, resort may properly, in my judgment, also be had to organisations outside such a company in order to gain the necessary information and expertise. If it is desired to set up a new plant devoted to manufacturing and selling a newly discovered product in an uncharted technical area, such as the particular artificial fibre, medical and biological fields here, that is in fact the procedure which a company may well follow in order to establish such manufacture with the minimum of time and expertise. That is exactly what was done here, as the evidence showed. The plaintiffs found it necessary to consult the Southern Research Institute and other institutes in the field of spinning fibres of this type, a thing of which they had insufficient previous experience themselves, and the defendants, when contemplating going into the business as rivals of the plaintiffs, found it necessary to acquire, at a considerable price, the know-how and information in the polylactide field, already explored by Du Pont, the latter being another of the very few organisations in the world concerned with these and similar medical products. Both Du Pont and the defendants thought they had a winner in polylactide, but were wrong. It will be appreciated that, in fact, many of those involved and taking part in the placing on the market of such a new product, which was artificial and had no previous equivalent in this respect, would be highly qualified scientists trained at least to university standard, with all that entails, and used to carrying out chemical and biological research work in research departments. That is what in fact happened in the case of both the plaintiffs' and defendants' artificial sutures here, and it would, to my mind, be highly misleading to suggest that there was in fact, in the present case, any body of "intermediately" skilled technicians to whom the specification could be addressed and whose existence must be assumed to be "obvious", as was assumed by the Court of Appeal in Valensi v. British Radio Corporation Ltd. [1973] R.P.C. 337. The correct view, in my judgment, which is consistent with the principle which the Court of Appeal must, I think, be presumed to have acted upon, is to hold as a matter of law (or, more precisely, to hold and find as a mixed quest of law and fact) that the answer to the question: "Who is the skilled addressee of the specification?", depends upon making an examination of the facts in each case, and in so doing regard must be paid primarily to the nature of the invention, to the nature and size of the industry concerned, and the way it is organised for the purposes of conducting research into and of producing and marketing its products. I follows that I consider the "instructed reader" in this case must be assumed to be a composite body of a number of technical people who could, in fact, be found at the time in the industry in question and whose qualifications are as I have set out above in general terms. This is the body whose pool of knowledge is clearly more comprehensive than that which might be expected to be held by a notional body of "intermediate" skilled technicians, who did not exist in fact and who could not have stood between the actual worker on the production line on the one hand, because there was no such line at the relevant time, and the specialist and highly skilled research workers who did exist and were the only people at that time in the field, on the other hand. It may, of course, be difficult in any particular case to decide whether a specific piece of knowledge ought to be assumed to be available to or to be part of the mental equipment of such a properly qualified body, but the court need not shrink from coming to a conclusion on the point when it has heard the relevant evidence, the principle being clear enough. That principle may be stated as follows. The piece of knowledge in question must not be the result of inventive concept or of prolonged research qualifying for the reward of valid letters patent but must be such as would be part of the mental equipment of, or would readily occur to the mind of, the notional appropriate skilled worker. Such skilled worker may notionally be one man or, as here, where several disciplines are involved, a team appropriately qualified and constituted having regard to the nature of the invention and the circumstances of the case and the art in question. In the latter event, as is, in my judgment, appropriate here, the test will be made against the corporate mental equipment and corporate mind of the team concerned." [Emphasis added]


Return to:

Cameron's IT Law: Home Page; Index

Cameron's Canadian Patent & Trade Secrets Law: Home Page; Index

JurisDiction Home Page