Minerals Separation v. Hyde, 242 U.S. 261 (1916)

by Dennis Crouch

Almost all the briefs filed in Amgen v. Sanofi cite to the 1916 Supreme Court decision in Minerals Separation v. Hyde, 242 U.S. 261 (1916). It is an interesting little case that primarily focuses on obviousness (i.e., “invention”), but also touches upon inventorship and sufficiency of disclosure.  In Amgen, the Supreme Court is tasked with reconsidering the law of enablement, and so it is this final issue that is most relevant.

Mined ore is typically a mixture of metals and various non-metallic gangue (often quartz).  Although folks had figured out various ways to separate the two, the solutions were not yet cost effective.  One form of separation was based upon the knowledge that certain oils tended to attach only to the metal.  Various prior patents used this law of nature to either cause the metal to float to the top of a liquid mixture or otherwise sink to the bottom.  But, those prior processes required a lot of oil; were not cost effective; and thus did not succeed in the marketplace.  Our patentees in this case are a trio of London metallurgists who developed their own approach of “froth flotation.”  They mixed in a very small amount of oil (0.5% of ore weight) into the powdered ore and then vigorously shook the mixture.  The shaking caused the oil to form air bubbles that rose to the top in a froth form.  And, because of the affinity between the oil and the metal, the metal power and flakes would line the surface of the frothed bubbles.  U.S. Pat. No. 835,120 (1906).

On the enablement issue, although the patentee had conducted tests on various oils and acids; agitation levels; addition of heat; etc, it was also clear that the method required refining for each different type of ore.  In particular, a user would need to conduct preliminary tests to figure out the amount of oil and level of agitation that works best.  The patent itself admitted that “in the concentration of any particular ore a simple preliminary test is necessary to determine which oily substance yields the proportion of froth or scum desired.’’

The Supreme Court considered this issue, but found the disclosure sufficient.

The composition of ores varies infinitely, each one presenting its special problem, and it is obviously impossible to specify in a patent the precise treatment which would be most successful and economical in each case. The process is one for dealing with a large class of substances and the range of treatment within the terms of the claims, while leaving something to the skill of persons applying the invention, is clearly sufficiently definite to guide those skilled in the art to its successful application, as the evidence abundantly shows. This satisfies the law.

Minerals Separation, 242 U.S. at 270-271.  In the same paragraph, the court also included a sentence on claim definiteness, using the same language of reasonable certainty that the Court later reiterated in Nautilus: “the certainty which the law requires in patents is not greater than is reasonable, having regard to their subject matter.”

The district court had also decided the case in favor of the patentee, concluding that “a range of quantities that leaves something to the judgment of the operator is all that can be described, and is sufficiently definite.”  Minerals Separation v. Hyde, 207 F. 956 (D. Mont. 1913), rev’d, 214 F. 100 (9th Cir. 1914), rev’d, 242 U.S. 261 (1916).  The issue does not appear to have been briefed to the Supreme Court, but the court addressed it anyway.

Both the District Court and the Supreme Court cite to Mowry v. Whitney, 81 U.S. 646 (1871).  In that case, Justice William Strong explained that a patent is not awarded simply for the act of invention. Rather, the inventor must also “teach the public how to practice it.”  Still, the court went on to explain that the specification is directed to those of skill in the art. Thus, disclosures insufficient the general public may still be sufficient to teach those already knowledgeable. “[I]t may leave something to their skill in applying the invention, but it should not mislead them.” Id.  In Mowry, the court concluded that the patent was valid despite “vague and uncertain directions” as to the amount of heat to add as part of a casting process.

But it is obvious that only vague and uncertain directions could have been given respecting the extent to which the heat is necessary to be raised. It must differ with the difference in the progress of cooling which has taken place before the wheels are removed from the moulds. . . . That, in the nature of things, must be left to the judgment of the operator.

Id.  In Minerals Separation, the Supreme Court also cited to Ives v. Hamilton, 92 U.S. 426 (1875).  In Ives the patent introduced a mechanism to impart a rocking motion a reciprocal saw being used in a saw mill.  The patentee used a “curved guide” but did not describe the exact nature of the curve.  In the case, the Supreme Court sided with the patentee and found the disclosure sufficient:

The complaint made by the defendants, that the patent is defective in not stating the nature of the curve for the guides, whether that of a circle or of some other figure … [is] not sufficient to affect its validity. Any good mechanic acquainted with the construction of sawmills, and having the patent and diagram before him, would have no difficulty in adopting the improvement, and making suitable curves.

Id.  The statutory text at the time was codified in R.S. Sec. 4888. The text is remarkably similar to the language found today in Section 112(a).  It required the the patentee to file:

a written description of the [invention or discovery], and of the manner and process of making, constructing, compounding, and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art or science to which it appertains, or with which it is most nearly connected, to make, construct, compound, and use the same; and in case of a machine, he shall explain the principle thereof, and the best mode in which he has contemplated applying that principle, so as to distinguish it from other inventions; and he shall particularly point out and distinctly claim the part, improvement, or combination which he claims as his invention or discovery.

R.S. Sec. 4888 (1910).