Case Comment

Marzone Chemicals Ltd. v. Eli Lilly and Co.

citation(s): (1978), 37 C.P.R. (2d) 37 (F.C.A. per Pratte, J.A.)

copyright 1997 Donald M. Cameron




The patent claimed a chemical which was useful as a herbicide.  Claim 7 merely gave the scientific formula or description of the new herbicide:

"7.     N,N-di-n-propyl 4-trifluoromethyl-2,6- dinitroaniline".

The Decision

At p. 38:

It is common ground that Dr. Soper made an important invention when he found trifluralin, the new chemical compound described in claim No. 7, and discovered that it could be used as a herbicide. Counsel for the appellants submits, however, that Dr. Soper did not invent trifluralin; his invention, he says, was merely the discovery of the herbicidal properties of that new substance. For this reason, counsel concludes that claim No. 7 is too broad and invalid as contravening the requirements of s. 36(2) of the Patent Act, R.S.C. 1970, c. P-4.

Dr. Soper certainly discovered that trifluralin could be used as a herbicide. The question is whether his invention was limited to that discovery.

Counsel for the appellants conceded that the discovery of a new and useful chemical compound may, in certain circumstances, be an invention giving the inventor the right to claim the new substance itself as his invention. He argued, however, that the discovery of trifluralin was not such an invention because, in his submission, while that substance had never been made before, it was nevertheless known and obvious.

The contention that trifluralin was known is based on evidence to the effect, as I understand it, that a competent chemist could, at any time, have written down its chemical formula. However, in that sense, all chemical compounds are known because, in theory, a competent chemist could write a list of all possible chemical compounds that might ever be brought into existence. This mere theoretical possibility does not, in my opinion, prevent the discovery of a new chemical compound from being an invention.

At p. 39:

Before trifluralin was discovered, Dr. Soper and many other scientists were trying to find a substance having certain specific herbicidal properties. No such substance was known to exist; nobody knew whether it could be made. Dr. Soper found that substance and made it. That was his invention and that is the invention that is described in claim No. 7.


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