services of the Crown, on terms to be before or after the use thereof agreed on, with the approval of the Treasury, between those officers or authorities and the patentee, or, in default of such agreement, on such terms as may be settled by the Treasury after hearing all parties interested."

This section, therefore, overrules the decision in Feather v. The Queen, 6 B. & S. 284 (1865), as the patent when granted will run against the Crown as well as its subjects, and the Crown can only use the invention patented by its officers, agents, contractors, or others, on compensating the patentee for such use.

The decision in Dixon v. London Small Arms Co., L.R. I App. Ca. 640 (1876), is also overruled, the Crown being now able to use an invention, on compensation by its contractors as well as its servants or agents, which was there decided it could not do; and a condition was therefore usually inserted by the Privy Council, on granting an extension of a patent, enabling the Crown to do this. The effect of this section will also make this condition no longer requisite.

CHAPTER XVI.

INFRINGEMENT.

THIS chapter is divided into three parts.

Part I.—The Infringement of a Patent.

Part II.-Proceedings in an Action for Infringement.
Part III.-Falsely representing an Article to be a Patent.

PART I.-The Infringement of a Patent.

The manner in which a patent can be infringed may be classed thus :

1. By a colourable imitation.

2. By importation.

3. By buying and selling by way of trade even inno-
cently patented articles.

4. Infringement through an agent.

1. By a Colourable Imitation.

imitation.

In Walton v. Potter, 1 Web. P.R. 586 (1841), Tindal, C.J., 1. Colourable lays down this rule concerning the infringement of a patent by the use of a colourable imitation of it. He says: "Where a party has obtained a patent for a new invention, or a discovery which he has made by his own ingenuity, it is not in the power of any other person, simply by varying in form or in immaterial circumstances the nature or subject-matter of that discovery, to obtain either a patent for it himself or to use it without leave of the patentee, because that would be in effect and substance an invasion of the right. And therefore what you have to look at is . . . . whether in reality, in substance and effect the defendants have availed themselves of the plaintiff's invention." This dictum is quoted with

Of a combination.

approval by Jessel, M.R., in Thorn v. Worthing Skating Rink Co., L.R. 6 Ch.D. 415 n. (1876), who applied it to the case then before him.

And in Newton v. Grand Junction Railway Co., 5 Exch. R. 334 (1846), Pollock, C.B., said: "In considering the question of infringement, all that is to be looked at is, whether the defendant has pirated a part of that to which the patent applies; and if he has used that part for the purposes for which the patentee adapted his invention, and for which he has taken out his patent, and if the jury are of opinion that the difference is merely colourable, it is an infringement."

And in Sellers v. Dickinson, 5 Exch. R. 324 (1850), Pollock, C.B., referring to an infringement of a combination, lays down this principle: "There may be an infringement by using so much of a combination as is material, and it would be a question for the jury whether that used was not substantially the same thing." And on page 326 he continues: "If a portion of a patent for a new arrangement of machinery is in itself new and useful, and another person, for the purpose of producing the same effect, uses that portion of the arrangement, and substitutes for the other matters combined with it another mechanical equivalent, that would be an infringement of the patent."

In Lister v. Eastwood, 9 L.T. N.S. 766 (1864), the direction of Erle, C.J., was held a correct exposition of the law in these cases. Williams, J., giving the judgment of the Court refusing a new trial, referring to the charge of the Chief Justice, which was complained of, said: "The Chief Justice, however, proceeded to tell the Jury that, in order to constitute an infringement, the defendant must not only have taken a new and material part of the combination, but must also have applied it to a purpose similar or analogous to that which the plaintiff's combination was intended to effect. We are of opinion that this was a correct exposition of the law.” And it is laid down in Parkes v. Stevens, L.R. 8 Eq. 367 (1869), by James, L.J., that "A valid patent for an entire combination of a process gives protection to each part thereof that is new and material to that process, which is really nothing more than stating in other words that you have not only no right to steal the whole, but you have no right to steal any part of a man's invention; and the question in every case is a question of fact-Is it really and substantially part of the invention ?" Lord Cairns, referring to this subject, says in Harrison v. Anderton Foundry Co., L.R. I App. Ca. 574 (1876): "If it is clear the claim is for a combination, and nothing but a combination, there is no infringement unless

the whole combination is used, and it is immaterial whether any or which of the parts are new.”

In Townsend v. Haworth, L.R. 12 Ch.D. 831 n. Jessel, M.R., laid down in his judgment: "It is only the combinations claimed that may not be used; the other elementary combinations may be used. . . . . You cannot complain of Subsidiary the use of subsidiary combinations unless they are within the and parts. purview of your claim."

In Lister v. Leather, 8 E. & B. 1033 (1858), Williams, J., giving the judgment on appeal referring to the use of subordinate parts of a combination, said: "The use of a subordinate part of a combination might be an infringement of the patent, if the part so used was new (by which we mean was new in itself, or in its effect, not merely in its application) and material."

In Clarke v. Aidie, L.R. 2 App. Ca. 320 (1877), Lord Cairns, referring to the case of an alleged infringer with regard to this point, says: "He might not take the whole of the instrument here described, but he might take a certain number of parts of the instrument described; he might make an instrument which in many respects would resemble the patent instrument, but would not resemble it in all its parts. And then the question would be either for a jury, or for any tribunal which was judging of the facts of the case, whether that which was done by the alleged infringer amounted to a colourable departure from the instrument patented, and whether in what he had done he had not really taken and adopted the substance of the instrument."

The following are a few cases on infringement by colourable imitation :

Sellers v. Dickinson, 5 Exch. R. 324 (1850).

The plaintiff's invention had an arrangement for stopping looms by means of the action of a clutchbox in combination with a break. The defendant's arrangement for the same purpose was by bringing a break in connection with a fly-wheel; this was held an infringement of the plaintiff's patent. Murray v. Clayton, L.R. 7 Ch. 570 (1872).

A patent for improvements in machinery for cutting bricks, by forcing the clay against the wires to cut it the size required for the brick, held to be infringed by a machine for cutting bricks by moving the wires themselves against the clay.

Barrett v. Vernon, 35 L.T. N.S. 755 (1876).

The plaintiff was a patentee for an invention for

combinations

Chemical equivalent.

Infringement.

No infringement.

stopping bottles containing aërated water, by means of a plug of hard wood having greater specific gravity than water. The defendants subsequently obtained a patent for an invention for the same purpose, but the stoppers used were of less specific gravity than water, and the stopping was effected by a weight applied to the stopper, making it heavier than the specific gravity of water. It was held this was a colourable imitation. Plimpton v. Malcolmson, L.R. 3 Ch.D. 555 (1876).

A patent for roller skates, the rollers being attached to the foot-stand in such a way that they could be made to turn in a circle by the rocking of the footstand acting on a steel spring. The defendant was selling roller skates similar, but with an india-rubber spring instead of a steel spring, producing the same effect, which was held an infringement.

United Telephone Co. v. Harrison, L.R. 21 Ch.D. 720 (1882).

The plaintiffs used, in a patented instrument for telephony, a diaphragm or tympan of mica to receive the air vibrations produced by the voice; below this was a cork of smaller size, and below the cork a piece of platina foil of the same size as the cork; and in a cavity or box below the platina was placed the substance which was used as a tension regulator. The defendants made and sold similar instruments, but dispensed with the mica diaphragm and the cork, the air vibrations being received directly on the platina foil, below which was placed the substance used as a tension regulator. At the date of the plaintiff's patent it was not known that the instrument would work without the mica diaphragm, which was a subsequent discovery. This was held an infringement of the plaintiff's patent.

Newton v. Grand Junction Railway Co., 5 Exch. R. 331 (1846).

The plaintiff's patent was for a soft metal lining, consisting of an alloy of tin, for boxes for axletrees. The defendants used a lining of tin and soldered it, which was held an infringement of the patent. Stevens v. Keating, 2 Web. P.R. 194 (1848).

The plaintiff's patent for the manufacture of cement by the process of combining gypsum, acid and alkali, was held infringed by a process of combining gypsum, sulphate of lime, and borax for the same purpose, borax being a known compound of acid and alkali. Unwin v. Heath, 5 H.L.Ca. 505 (1855).

A patent for the manufacture of cast-steel by use