440 
Patents^ 
of any machine, he shall fully explain the principle, and the seve- 
ral modes, in which he has contemplated the application of that 
principle or character, by which it may be distinguished from Other 
inventions; and he shall accompany the whole with drawings and 
written references, where the nature of the case admits of draw- 
ings, or with specimens of the ingredients, and of the composition 
of matter, sulhcient in quantity for the purpose of experiment, 
where the invention is of a composition of matter : which descrip- 
tion, signed by himself, and attested by two witnesses, shall be 
filed in the office of the secretary of state, and certified copies 
thereof shall be competent evidence, in all courts, where any mat- 
ter or thing, touching such patent right, shall come in question. 
And such inventor shall, moreover, deliver a model of his mac aine, 
provided the secretary shall deem such model to be necessary. 
4. Sect. IV. It shall be lawful for any inventor, his executor 
or administrator, to assign the title and interest in the said inven- 
tion, at any time, and the assignee having recorded the said assign- 
ment, in the office of the secretary of state, shall thereafter stand 
in the place of the original inventor, both as to right and respon- 
sibility, and so the assignees of assigns, to any degree. 
Sect. V. is repealed and supplied. [See postea 12.] 
5. Sect. VI. Provided always^ That the defendant in such 
action shall be permitted to plead the general issue, and give this 
act and any special matter, of which notice in writing may have 
been given to the plaintiff or his attorney, thirty days before trial, 
in evidence, tending t© prove, that the specification, filed by the 
plaintiff, does not contain the whole truth relative to his discovery, 
or that it contains more than is necessary to produce the describ- 
ed effect, which concealment or addition shall fully appear to have 
been made, for the purpose of deceiving the public, or that the 
thing, thus secured by patent, was not originally discovered by 
the patentee, but had been in use, or had been described in some 
public work, anterior to the supposed discovery of the patentee, 
or that he had surreptitiously obtained a patent for the discovery of 
another person : In either of which cases, judgment shall be ren- 
dered for the defendant, with costs, and the patent shall be declar- 
ed void. 
6. Sect. VII. Where any sta,te before its adoption of the pre- 
sent form of government, shall have granted an exclusive right to 
any invention, the party claiming that right, shall not be capable 
of ertaiving an exclusive right under this act, but on relinquish- 
ing his right, under such particular state, and of such relinqui^^- 
