Syllabus.

of the section levying the duty of twenty per centum ad valorem, unless they were shown to have been used exclusively for that purpose, is not insisted upon by the Solicitor General in this court. It was very properly abandoned, the charge of the court upon that point being, in our opinion, clearly right. The judgment of the Circuit Court is accordingly

Affirmed.

TILGHMAN v. PROCTOR.

PROCTOR v. TILGHMAN.

APPEALS FROM THE CIRCUIT COURT OF THE UNITED STATES FOR THE SOUTHERN DISTRICT OF OHIO.

Nos. 537, 548. Argued November, 3, 4, 5, 1886. - Decided March 19, 1888.

One having an interest in all fees and other sums to be recovered under a patent, but not shown to have any interest, legal or equitable, in the patent itself, need not be made a party to a bill in equity for its infringe

ment.

Upon a bill in equity by the owner against infringers of a patent, the plaintiff, although he has established license fees, is not limited to the amount of such fees, as damages; but may, instead of damages, recover the amount of gains and profits that the defendants have made by the use of his invention, over what they would have had in using other means then open to the public and adequate to enable them to obtain an equally beneficial result.

Upon a bill in equity for infringing a patent, if the defendants have gained an advantage by using the plaintiff's invention, that advantage is the measure of the profits to be accounted for, even if from other causes the business in which the invention was employed by the defendants did not result in profits; and if the use of a patented process produced a definite saving in the cost of manufacture, they must account to the patentee for the amount so saved.

The liability of infringers of a patent to account to the patentee for all the profits, gains and savings, which they have made by the use of his invention during the whole period of their infringement, is not affected by the fact that in the midst of that period an erroneous decision was made in favor of a distinct infringer, in no way connected with these defendants.

The conclusions of a master in chancery, depending upon the weighing of

Opinion of the Court.

conflicting testimony, have every reasonable presumption in their favor, and are not to be set aside unless there clearly appears to have been error or mistake on his part.

In determining the amount of gains and profits derived by infringers of a patent from the use of the invention, over what they would have made in using an old process open to the public, the expense of using the new process is to be ascertained by the manner in which they have conducted their business, and not by the manner in which they might have conducted it; but the cost at which they used the old process is not conclusive against them, if other manufacturers used that process at less cost. As a general rule, in taking an account of profits against an infringer of a patent, interest is not to be allowed before the date of the submission of the master's report, but only after that date and upon the amount shown to be due by his report and the accompanying evidence. The other questions decided were questions of fact.

IN EQUITY. These were cross appeals from the decree entered (on the report of a master) in the execution of the mandate of this court in the cause reported in 102 U. S. 707. The case is stated in the opinion of the court.

Mr. Francis T. Chambers and Mr. George Harding for Tilghman.

Mr. Robert H. Parkinson and Mr. William M. Ramsey for Proctor and others.

MR. JUSTICE GRAY delivered the opinion of the court.

This was a bill in equity, filed June 26, 1874, by Richard A. Tilghman against William Proctor and four others, copartners under the name of Proctor & Gamble, praying for an injunction, for an account of profits, and for damages, for the infringement of letters patent, originally granted to Tilghman for fourteen years from January 9, 1854, and afterwards extended to January 9, 1875, for the process of manufacturing fat acids and glycerine from fatty bodies by the action of water at a high temperature and pressure.

The infringement complained of in this suit was from May 1, 1870, to January 8, 1875. Similar suits by this plaintiff against other defendants had been maintained by the Circuit Courts for the Southern Districts of Ohio and of New York

Opinion of the Court.

in 1862 and 1864 respectively. Tilghman v. Werk, 2 Fisher Pat. Cas. 229; Tilghman v. Mitchell, 2 Fisher Pat. Cas. 518. In the suit in New York, a final decree for an account of profits was entered by the Circuit Court on September 1, 1871. Tilghman v. Mitchell, 9 Blatchford, 1, 18; S. C. 4 Fisher Pat. Cas. 599, 615. On March 2, 1874, that decree was reversed in this court, by the opinion of four justices against three, two judges not sitting, upon the hypothesis that Tilghman's patent was limited to the apparatus therein described, and that the use of an apparatus similar to that used by the present defendants was not an infringement. Mitchell v. Tilghman, 19 Wall. 287, 419, iii.

In the case at bar, the Circuit Court, on December 2, 1874, following the decision of this court in Mitchell v. Tilghman, made a decree dismissing the bill. But, on appeal from that decree, this court, at October term, 1880, by a unanimous opinion, overruled its decision in Mitchell v. Tilghman, and adjudged that Tilghman's patent was a valid one for a process, and not merely for the particular apparatus described in the specification; that that apparatus could be operated to produce a beneficial result; that the defendants had infringed the plaintiff's patent; and, therefore, that the decree of the Circuit Court be reversed, and the case remanded with directions to enter a decree for the plaintiff in conformity with that opinion. Tilghman v. Proctor, 102 U. S. 707. There is nothing in the record before us to induce any change or modification of the conclusions then announced.

By making a few extracts from that opinion, the questions now before us will be the better understood.

"The patent in question relates to the treatment of fats and oils, and is for a process of separating their component parts so as to render them better adapted to the uses of the arts. It was discovered by Chevreul, an eminent French chemist, as early as 1813, that ordinary fat, tallow and oil are regular chemical compounds, consisting of a base which has been termed glycerine, and of different acids, termed generally fat acids, but specifically stearic, margaric and oleic acids. These acids, in combination severally with glycerine, form stearine,

Opinion of the Court.

margarine and oleine. They are found in different proportions in the various neutral fats and oils; stearine predominating in some, margarine in others, and oleine in others. When separated from their base (glycerine) they take up an equivalent of water, and are called free fat acids. In this state they are in a condition for being utilized in the arts. The stearic and margaric acids form a whitish, semi-transparent, hard substance, resembling spermaceti, which is manufactured into candles. They are separated from the oleic acid, which is a thin oily fluid, by hydrostatic or other powerful pressure; the oleine being used for manufacturing soap, and other purposes. The base, glycerine, when purified, has come to be quite a desirable article for many uses." 102 U. S. 708, 709.

The substance of Tilghman's discovery and invention was thus summed up by the court: "That the fat acids can be separated from glycerine, without injury to the latter, by the single and simple process of subjecting the neutral fat, whilst in intimate mixture with water, to a high degree of heat under sufficient pressure to prevent the water from being converted into steam, without the employment of any alkali or sulphuric acid, or other saponifying agent; the operation, even with the most solid fats, being capable of completion in a very few minutes when the heat applied is equal to that of melting lead, or 612° Fahrenheit; but requiring several hours when it is as low as 350° or 400° Fahrenheit. The only conditions are, a constant and intimate commixture of the fat with the water, a high degree of heat, and a pressure sufficiently powerful to resist the conversion of the water into steam. The result is, a decomposition of the fatty body into its elements of glycerine and fat acids, each element taking up the requisite equivalent of water essential to its separate existence, and the glycerine in solution separating itself from the fat acids by settling to the bottom when the mixed products are allowed to stand and cool. In this process a chemical change takes place in the fat in consequence of the presence of the water and the active influence of the heat and pressure upon the mixture." pp. 712,

713.

The court spoke of the different forms of apparatus, men

Opinion of the Court.

tioned in Tilghman's patent, or used by the defendants, as follows:

"The apparatus described" in the patent "consists of a coil of iron pipe, or other metallic tubing, erected in an oven or furnace, where it can be subjected to a high degree of heat; and through this pipe the mixture (of nearly equal parts of fat and water), made into an emulsion in a separate vessel by means of a rapidly vibrating piston or dasher, is impelled by a force-pump in a nearly continuous current, with such regulated velocity as to subject it to the heat of the furnace for a proper length of time to produce the desired result; which time, when the furnace is heated to the temperature of 612° Fahrenheit, is only about ten minutes. The fat and water are kept from separating by the vertical position of the tubes, as well as by the constant movement of the current; and are prevented from being converted into steam by weighting the exit valve by which the product is discharged into the receiving vessel, so that none of it can escape except as it is expelled by the pulsations produced by the working of the force-pump. Before arriving at the exit valve, the pipe is passed, in a second coil, through an exterior vessel filled with water, by which the temperature of the product is reduced. After the product is discharged into the receiving vessel, it is allowed to stand and cool until the glycerine settles to the bottom and separates itself from the fat acids. The latter are then subjected to washing and hydraulic pressure in the usual way." pp. 718, 719.

"It is evident that the passing of the mixture of fat and water through a heated coil of pipe standing in a furnace is only one of several ways in which the process may be applied. The patentee suggests it as what he conceived to be the best way, apparently because the result is produced with great rapidity and completeness. But other forms of apparatus, known and in public use at the time, can as well be employed without changing the process. A common digester, or boiler, can evidently be so used, provided proper means are employed to keep up the constant admixture of the water and fat, which is a sine qua non in the operation." pp. 719, 720.