Mineral Separation Corp. v. Magma Copper Co.
280 U.S. 400 (1930)

Annotate this Case

U.S. Supreme Court

Mineral Separation Corp. v. Magma Copper Co., 280 U.S. 400 (1930)

Mineral Separation Corp. v. Magma Copper Co.

No. 71

Argued January 9, 1930

Decided February 24, 1930

280 U.S. 400

Syllabus

1. The effect of a patent as a disclosure depends on what is made known by the specification, and is not limited to the precise scope of the claims. P. 280 U. S. 402.

2. Patent No. 835, 120, of the Minerals Separation, Ltd. (sustained by this Court, 242 U. S. 242 U.S. 261; 250 U. S. 250 U.S. 336), disclosed the general fact that oils and other substances having a preferential affinity for the metalliferous particles in ores, can be used to separate them, in a froth, from the gangue by mixing such substances with the pulverized ore in water and agitating the mixture, the particular substance most effective with the particular ore and the limit of the quantity of it to be used being determined by preliminary tests. P. 280 U. S. 401.

3. This disclosure anticipated Patent No. 962,678, here in suit, which claims a similar process but relies on "mineral frothing agents" that dissolve in the water. The later patent cannot be sustained upon the ground that the selective substances referred to in the earlier one are oils and upon the assumption that oils function by coating the metalliferous particles and that the other substances function by "modifying the water." P. 280 U. S. 403.

4. The rule attributing weight to the commercial success of a patent as evidence of invention held inapplicable here on the special facts of the case. P. 280 U. S. 404.

30 F.2d 67 affirmed.

Certiorari, 279 U.S. 832, to review a decree of the circuit court of appeals, which reversed a decree of the district court, 23 F.2d 931, in favor of the above-named petitioner in a suit for alleged infringement of its patent.

Page 280 U. S. 401

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