234 Memoir of the Life of Eli Whitney. 



dence given in support of it, establishes a presumption, that he must 

 have derived the plan of his machine from a similar one used in the 

 cotton manufactories in Great Britain. 



In support of the second ground of defence, evidence was pro- 

 duced to show that Mr. Whitney now uses, and that the defendant 

 also.uses, teeth, formed of circular ii'on plates, instead of teeth made 

 of wire. And it was contended that this is a departure from the 

 specification, and an improvement on the original discovery, which 

 destroys the merit of that discovery, and the validity of plaintiff's 

 patent. It was also insisted that the plaintiff had concealed the best 

 means of producing the effect contemplated. 



Mr. Noel of counsel for the plaintiff, in opposition to the first 

 ground of defence, stated two points — First : That if the principle 

 be the same, yet the plaintiff's application of that principle being new, 

 and for a distinct purpose, has all the merit of an original invention. 

 Second : That the principle of Mr. Whitney's machine is entirely 

 different from that exhibited by defendant. 



He defined the term principle, as applied to mechanic arts, to 

 mean the elements and rudiments of those arts, or in other words, 

 the first ground and rule for them. That for a mere principle, a 

 patent cannot be obtained. That neither the elements, nor the man- 

 ner of combining them, nor even the effect produced, can be the 

 subject of a patent, and that it can only be obtained for the apphca- 

 tion of this effect to some new and useful purpose. 



To prove this position, several examples were stated of important 

 inventions, for which patents had been obtained, which had resulted 

 from principles previously in common use, and an argument of a 

 celebrated Judge, at Westminster Hall, was cited, in which it is as- 

 serted "that two thirds, or three fourths of all patents granted since 

 the statute passed, are for methods of operating and manufacturing, 

 producing no new substances, and employing no new machinery ;'* 

 and he adds, in the significant words of Lord Mansfield, " a patent 

 must be for method, detached from all physical existence whatever." 



The second point was principally relied on, to wit : That the prin- 

 ciple of Mr. Whitney's machine is distinct from that produced by 

 defendant, and new in its origin. 



It consists of teeth, or sharp metallic points, of a particular form 

 and shape, and its application is to separate cotton from the seed ; 

 whereas the principle of the model exhibited by the defendant, 

 and of every other machine before invented, and used for the same. 



