Gravity or Dilution Separators. 17 



the raising of the cream, it may be well to look into the matter of 

 the possibility of such a patent being granted. 



In the language of the patent office an invention, in order to 

 receive a patent, must present " novel, useful, and patentable sub- 

 ject matter." Waiving altogether or granting entirely the useful- 

 ness and patentability of this process let us look only into its novelty. 

 The pi-ocess was certainly well known as early as 1890, for in that 

 year it was the subject of investigation and report by at least three 

 Agricultural Experiment Stations * in widely separated parts of the 

 country. It has been argued that these reports, since they did not 

 recommend the practice, should not be considered as evidence that 

 the process was " well known and in common use." But one, at 

 least, of the publications cited f did strongly recommend the process, 

 and if recommendation were necessary to constitute publicity it 

 would be easy to find it in the agricultural and dairy press of that 

 period. The late Col. F. D. Curtis, to the personal knowledge of 

 the writer, strongly reconnnended the dilutive process at numerous 

 farmers' institutes in this state during the winters of 1889--90 and 

 1890-91, and frequently also recommended it in the press.:}: 



Prof. E. F. Ladd, then of the State Agricultural Experiment 

 Station at Geneva, now of the North Dakota Agricultural Experi- 

 ment Station, also recommended § it under certain conditions, and it 

 was frequently mentioned by other writers. It is also recommended 

 for use in connection with the Cooley creamer in circular No. 211: 

 of the Vermont Farm Machine Co., page 10. Under date of May 

 31, 1899, Mr. N. G. Williams, the manager of the company, informs 

 me concerning the above. " These particulars were in April, 1890, 

 and have been published in our circulars ever since. We had 

 recommended it (dilution) before this." The process was then well 

 known over large portions of the country at least nine years ago, 

 but had almost completely disappeared from public view till revived 

 by these boomers of patent cans about two years ago. 



*Vt. Agr. Expt. Sta. Newspaper Bulletin No. 3; Cornell Univ. Agr. Expt. 

 Sta. Bull. No. 20, and Univ. of Illinois Agr. Expt. Sta. Bull. No. 12, p. 876. 



tVt. Agr. Expt. Sta. Bull. No. 3. 



XGountry Gentleman, Dec. 12, 1889, p. 945; July 31, 1890, p. 611, and Aug. 21, 

 1890, p. 662. 



%Bural New- Yorker, Aug. 16, 1890, p. 527. 



