Marchand v. Emken’s Empirical Analysis

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Most-quoted passages

The sentences later courts lift from this opinion, ranked by how many decisions quote each — the parts of the opinion doing the work. These counts are smaller than the citation total above because most of the 1 citing decisions cite the case generally; a passage count includes only decisions quoting that exact language verbatim.

1. “The question, then, seems to be narrowed down to this: Does it constitute invention to stir, by a well-known and simple mechanical device, what had before been stirred by hand ? The complainant desired to manufacture in large quantities what had before been produced chiefly in the laboratory. He knew how hydrogen peroxide had been made; every step in the formula was familiar. A mixture that needed stirring, and a vessel provided with a revolving stirrer, were ready at his hand. He put the former into. the latter. This was all. The object of agitating the liquid, while making hydrogen peroxide, is to keep the barium, which is three times as heavy as water, suspended in the acid, so that its particles may come in contact with the particles of acid. Whether they come in contact while going round, rising, settling or remaining stationary, can make no difference. Divest the case of the air of "mystery with which it is environed, and it seems simple enough. The complainant’s predecessors knew that to keep the barium up in the solution they must stir it. The complainant knew this. Unlike them, however, he manufactured on a scale large enough to make it essential to employ a power-shaft. ' The oar-shaped sticks • which formerly went round and round by hand now go round and round by machinery.”

   1 later decision quote this exact passage
   e.g. Marchand v. Emken

2. “It is not pretended that the complainant discovered hydrogen peroxide, or the method of adding barium, mixed with water, from time to time, to the diluted acid, or the necessity for stirring or agitating the liquid. Neither did he invent the obliquely bladed screw, the hemispherical receptacle, the jacketing vessel or any part of the apparatus described in the specification. All this was old and well known. The patent itself illustrates how extremely circumscribed was the theatre of invention.”

   1 later decision quote this exact passage
   e.g. Marchand v. Emken

3. “1. The method of making hydrogen peroxide by cooling the acid solution, imparting thereto a continuous movement of rotation, as well in vertical as in horizontal planes — such, for example, as imparted by a revolving screw in a receptacle — and adding to said acid solution the binoxidc in small quantities, while maintaining the low temperature and the rotary or eddying movements, substantially as described,”

   1 later decision quote this exact passage
   e.g. Marchand v. Emken