
86 U.S. 433 (____)
19 Wall. 433
KLEIN
v.
RUSSELL.
Supreme Court of United States.

*447 Mr. Matthew Hale, with whom was Mr. J.M. Dudley, for the plaintiff in error.
*454 Mr. H.E. Smith, contra.
*463 Mr. Justice SWAYNE delivered the opinion of the court.
The action was for the infringement of a reissued patent. The plaintiff in error was the defendant in the court below. A verdict and judgment were rendered against him. In the progress of the trial he took numerous exceptions. We have considered them, and will proceed to dispose of the case.
There was no error in the refusal of the court to direct a verdict for the defendant. The evidence is fully set out in the record. It was well remarked by the circuit judge, in deciding the motion for a new trial, that "the conflict of evidence upon the questions of fact is very great, and made it a very proper case for submission to the jury." Where it is entirely clear that the plaintiff cannot recover, it is proper to give such a direction, but not otherwise.
It is insisted, in this connection, that the reissue is void, because it was not for the same invention as the original patent.
This point does not appear to have been taken in the court below, and, therefore, cannot be made here. No instruction was asked or given touching the subject. It is to be presumed, until the contrary is made to appear, that the commissioner did his duty correctly in granting the reissued patent.
The question put to Uriel Case, and his answer, were within the proper limits of a cross-examination.[*]
The question to Place was proper, and his answer was not objected to. His answer as to his connection with the paper to which he referred also passed without objection. But it is insisted that it was error to require him to state its contents, *464 no notice to produce it having been given. To this there are two answers: It was an incidental and collateral matter drawn out to test the temper and credibility of the witness. It in no wise affected the merits of the controversy between the parties. The witness stated that he did not know who signed the paper. The contents could not, therefore, have operated to the injury of the defendant.
The question to Porter involved the novelty, utility, and modus operandi of the alleged invention of the plaintiff, and the answer was competent evidence.
Elaborate instructions covering the entire case were given to the jury. None of them were excepted to by the defendant.
Numerous instructions were asked by his counsel. An exception was taken in relation to each one of them, and is assigned for error.
We shall refer to them as they are numbered in the record.
I. That the patent is for "the treatment of bark-tanned sheep and lamb skins, by the employment of fat liquor, and if the jury believe such treatment was known to others more than two years before the plaintiff applied for his patent, his patent is void." This instruction was properly refused. It stated inaccurately the rule of law which it involved. A patent relates back, where the question of novelty is in issue, to the date of the invention, and not to the time of the application for its issue. The jury had already been sufficiently instructed upon the subject. The instruction assumes that the reissue was for the use of fat liquor, without reference to the point whether it were hot or cold. This renders it necessary to construe the patent with a view to the solution of that question.
The original specification declared that the invention consisted "in a novel treatment of bark-tanned lamb or sheep skins." The patentee said: "The process I adopt, and which constitutes my invention, is as follows: I take of `fat liquor,' obtained in scouring deerskins after tanning in oil, say ten gallons, and warm the same to or near the boiling-point. I then add to such heated fat liquor eight ounces of *465 sal soda, twelve ounces of common salt, one pint of soft soap, and four ounces of Venetian red, and stir and mix these several ingredients with the fat liquor." The claim is as follows: "What is here claimed, and desired to be secured by letters-patent, is the process substantially as herein described of treating bark-tanned lamb or sheep skins by means of a compound, and applied essentially as specified."
With this specification and claim, it was apprehended that the patent did not cover the use of heated fat liquor alone  which the patentee claimed as a part of his invention  but that it would be held to cover the use of such heated liquor only in combination with the ingredients specified. If so, the omission of any one, or all, of the ingredients would have given immunity to an infringer. To remedy this defect the reissue was procured. In the specification in that case the patentee says: "My invention consists in a novel treatment of what is known as bark-tanned lamb or sheep skin."
"The principal feature of my invention consists in the employment of what is known amongst tanners as fat liquor, which is ordinarily obtained by scouring deerskins, after tanning in oil, but which, when it is not convenient to obtain in this manner, may be produced as a liquor having the same character  obtained by the cutting of oil with a suitable alkali. In treating leather with the `fat liquor,' it is desirable to heat the liquor to or near the boiling-point, and it is preferred to use the same in connection with other ingredients. Thus, for instance, there may be added to each ten gallons of such heated fat liquor, eight ounces sal soda, twelve ounces common salt, one pint of soft soap, or an equivalent quantity of hard soap, four ounces of Venetian red; such ingredients to be well stirred and mixed with the fat liquor."
The claims are as follows:
"1. The employment of fat liquor in the treatment of leather, substantially as specified.
"2. The process, substantially as herein described, of treating bark-tanned lamb or sheep skins by means of a *466 compound composed and applied essentially as specified." The mode of application prescribed in both specifications is the same.
The first claim, it has been argued, is for the use of fat liquor generally, hot or cold. If it be for the former only, the patent may be valid; while, if for the latter, it may be too broad, and, therefore, void.
The counsel for the patentee insists that the claim is limited to fat liquor in a heated state. The subject is to be examined in the light of both specifications and of both sets of claims. The court should proceed in a liberal spirit, so as to sustain the patent and the construction claimed by the patentee himself, if this can be done consistently with the language which he has employed.
The original specification and claim were clearly confined to heated fat liquor. The law[*] required that the reissue should be for the same invention as the original patent. It is to be presumed the commissioner did his duty. If the reissue be for fat liquor generally, it is for a thing then patented for the first time, and the patent involves a violation of the law.
The second specification says: "The principal feature of the invention is the employment of `fat liquor.'" It then proceeds to direct how the liquor shall be prepared. In doing this it is said "it is desirable to heat the liquor to or near the boiling-point."
This is the foundation of the first claim, which is for "the employment of fat liquor in the treatment of leather, substantially as specified." The heated condition of the liquor is before distinctly specified, and if it be applied in any other state its condition will not be as specified, either exactly or substantially. After the words "boiling-point," the specification proceeds: "And it is preferred to use the same in connection with other ingredients. Thus, for instance, there may be added to each ten gallons of such heated fat liquor," &c. The ingredients are then named. This is the ground *467 of the second claim, to wit: "The process substantially as herein described of treating bark-tanned lamb or sheep skins by means of a compound composed and applied essentially as specified." Here heated fat liquor is clearly one of the constituents of the compound. A chemist proved on the trial that heat was an element essential, in a large degree, to the efficacy and utility of both the simple liquor and the compound, when so applied. We think the better opinion is, that the first claim was intended to cover, and does cover, only the use of heated liquor.
The first instruction might well have been refused for the reason, also, that it was too broad as to this point.
II. The next prayer and the action of the court are thus set forth in the bill of exceptions:
"2. The defendant's counsel also requested the said judge to charge that the proper construction of the patent is that the fat liquor should be applied at or near the boiling-point, and if the jury believe that the application of fat liquor at such a temperature to leather is injurious and pernicious, the patent is void for want of utility, and the defendant entitled to a verdict; but the said judge refused so to charge the jury, but modified the said request and instructed the jury that the proper construction of the second claim of the patent, so far as it relates to the application of heat, is that the compound, composed of fat liquor and the other ingredients required, should be applied at or near the boiling-point, under the common knowledge of persons skilled in the art of treating this leather, to procure softness and pliability, would make them wait until it was partially cooled before its application, and if the jury believe that the application of fat liquor at such a temperature to leather as is required by the specification under this qualification is injurious and pernicious, the patent is void for want of utility, and the defendant entitled to a verdict; and the counsel for defendant then and there duly excepted."
We think this ruling of the court was correct.
III and IV. These exceptions are sufficiently answered by what was said by the Circuit Court as to the second prayer.
*468 V. This instruction was properly modified. The state of the evidence hardly justified the judge in giving any instruction upon the subject to which it related.
The remaining five exceptions may be grouped and disposed of together. Neither of them requires any special remark.
We are satisfied with the rulings of the learned judge who tried the case as to each and all of them.
We find nothing in the record of which the plaintiff in error has a right to complain.
JUDGMENT AFFIRMED.
Dissenting, Justices FIELD and HUNT.
NOTES
[*]  Johnston v. Jones, 1 Black, 210.
[*]  Act of 1836, § 13, 5 Stat. at Large, 122.
