To entitle an individual to an exclusive right, under the Patent Law, his invention must be substantially different from any machine or thing in use.

A patent is void where, in his specifications, the patentee claims more than he has invented.

Under the Patent Law of 1836, a patent which contains corrected specifications,
has relation back, and, for all legal purposes, covers the whole time, from
the emanation of the first patent, which, for defective specifications, had been
declared void.

In such case a contract to sell the right is made good by the second patent.
A patent to be valid, must be of some utility.

The books of a party are not evidence, unless made so by a call to produce
them, &c.

A verdict will not be set aside where the evidence conflicts. It was for the jury to weigh the evidence. A declaration must contain a statement of facts, which, in law, gives the plaintiff a right to recover.

This is the question to be answered on a demurrer. But after verdict, defects, in substance, are cured, if, from the issue in the case, the facts omitted, or defectively stated, may fairly be presumed to have been proved on the trial.

Stanley v. Whipple. 2 McLean.

Where a contract binds the defendant to pay five dollars for each stove sold, as as in this case, the special contract need not be declared on; the amount received may be recovered on the general count for money had and received:

MR. CHASE appeared for the plaintiff, and Messrs. Storer and Eells for the defendant.

OPINION OF THE COURT.

The defendant's counsel moved the Court for a new trial on the following grounds:

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*First: That the verdict of the jury is against law and evidence;

Second: The damages given by the verdict are excessive; Third: Because the Court erred in its instruction to the jury to exclude the evidence from the defendant's books;

Fourth Because the Court erred in its instruction to the jury, that the second patent, if valid, had relation back to the time when the first patent was obtained.

The Court will consider the first and fourth grounds in connection.

The contract, on which this action is brought, is dated the 3d of October, 1832, in which Stanley agrees to sell to the defendant the right of making and vending a stove, for which he claims a patent, (which patent is not yet obtained,) in the city of Cincinnati, Ohio, &c., for which the defendant agrees to pay five dollars for each stove that he shall make and sell, &c.

The plaintiff, after proving the contract, and giving it in evidence, introduced his patent, dated the 28th November, 1836.

This patent is objected to, on the ground that its date is long subsequent to the date of the contract; and, it is contended, that it does not make good the right of the plaintiff