vention and whether or not an attempted joinder is permissible, an application may be found defective on account of an improper joinder, and a patent upon it may be refused. In such cases the inventor may amend his application by striking out such of the inventions as it has been decided cannot be joined with the others, and may then make them the subjectsmatter of separate applications, inserting into each, where the inventions all relate to a common object, specific disclaimers of the inventions severally covered by the others.1 When this amendment appears necessary on the face of the original application, it may be ordered before any action on the merits; otherwise, at any time before the final issue of the patent.

SECTION V.

OF THE APPLICATION: THE DESCRIPTION OF THE INVENTION.

§ 480. The Specification: its Importance.

The specification is the most important portion of the application. Not only does it serve as the basis of all the proceedings in the Patent Office and thus determine the right of the inventor to a patent, it also becomes a portion of the patent when granted, and as such fixes and defines the rights of th inventor and the public as against each other. In view of its importance, and in order to secure to it such characteristics as shall enable it to perform its proper functions both before and after the issue of the patent, numerous rules have been established concerning its form and contents which must be strictly observed.1

§ 479. That where distinct inventions are embraced in the same application the application must be divided, see Ex parte Preston (1880), 17 O. G.

853;
Ex parte Siemens (1877), 11 O. G.

969.

That on a division of the application disclaimers must be filed with each division, excluding the matter not claimed therein, see Ex parte Finch

(1883), 26 O. G. 273. See also § 467, note 2, ante.

That a division being once made the excluded matter cannot be reinstated, see Ex parte Preston (1880), 17 O. G. 853.

§ 480. That the rules of the Patent Office assume that all parts of the speci fication will conform to the statutes and rules, see Ex parte Crandall (1886), 35 O. G. 625.

§ 481. The Specification Sets Forth the Contract between the

Public and the Patentee: its Twofold Object.

The functions of a specification and the propriety of the rules which govern it are evident from the nature of a patent. A patent is a contract between the inventor and the public, by which the inventor, in consideration that the exclusive use of his invention is secured to him for a limited period of time, confers upon the public the knowledge of the invention during that period and an unrestricted right to use it after that period has expired.1 The public, on the other hand, acting through the government, agree with the inventor that, in consideration of his immediate bestowal upon them of a full knowledge of the invention and of the entire right to use it after the term named in his patent is at an end, they will protect him in its exclusive use during the life of his patent. In this contract resides the whole force and benefit of the patent to both parties. The specification is the instrument in which the terms of these mutual considerations and promises are declared, and on its completeness and accuracy depends the validity and the value of the contract itself. Its object is thus twofold: (1) To place the invention fully within the knowledge of the public; (2) To define the exact limits of that exclusive use which the public has undertaken to protect. All the rules into whose discussion we are now about to enter are intended to secure the accomplishment of these two objects.2

§ 481. 1 In Page v. Ferry (1857), 1 Fisher, 298, Wilkins, J.: (306) "The patent may be considered in the light of a deed from the government, the consideration of which is the invention specified; and the patentee is bound to communicate it, by so full, clear, and exact a description, with drawings and models, that it shall be within the comprehension of the public at the expiration of the patent; for at that period his invention becomes public property. The exclusive privilege is not conferred merely as a reward of genius, and for the encouragement of useful inventions and improvements in arts and manu

factures, but also embraces the public benefit." See also Wintermute v. Redington (1856), 1 Fisher, 239; Gibson v. Brand (1842), 1 Web. 627; Walton v. Potter (1841), 1 Web. 585.

2 In Tucker v. Tucker Mfg. Co. (1876), 4 Clifford, 397, Clifford, J.: (400) “Exactitude in the description of an invention is required for three reasons: 1. That the government may know what they have granted, and what will become public property when the term of the monopoly expires; 2. That licensed persons desiring to practise the invention may know during the term how to make, construct, and

§ 482. The Specification: its Two Divisions the Description

and the Claim.

Having these two objects to fulfil, a specification is naturally divided into two parts, not wholly independent of each other, but sufficiently distinct to be capable of, and to require, a separate consideration. These two parts are known as the Description, and the Claim. It is the office of the Description to communicate to the public the knowledge of the invention. It is the office of the Claim to define the limits beyond which the public cannot pass without invading the exclusive rights of the inventor. These two parts are not simple repetitions of each other. While the Description necessarily use the invention; 3. That other and subsequent inventors may know what part of the field of invention is unoccupied." 10 0. G. 464 (464); 2 Bann. & A. 401 (403).

See also Mabie v. Haskell (1865), 2 Clifford, 507; Forbes v. Barstow Stove Co. (1864), 2 Clifford, 379; Judson v. Moore (1860), 1 Bond, 285; 1 Fisher, 544; Wayne v. Holmes (1856), 2 Fisher, 20; 1 Bond, 27; Morton v. Middleton (1863), 1 Cr. S. 3d Series, 725; Hills v. London Gas Light Co. (1860), 5 H. & N. 312; Holmes v. London & N. W. R. R. Co. (1852), Macrory, P. C. 13; Neilson v. Thompson (1841), 1 Web. 278; Hornblower v. Boulton (1799), 8 T. R. 95; 1 Abb. P. C. 98; Arkwright v. Nightingale (1785), 1 Web. 60; 1 Abb. P. C. 24.

§ 482. 1 That the applicant for a patent must fully describe and exactly claim his actual invention; and when he has done this the requirements of the law are satisfied, see Ex parte Skinner (1881), 19 O. G. 662; Wyeth v. Stone (1840), 1 Story, 273; 2 Robb, 23.

That the primary object of a specification is to describe the invention, see Aultman v. Holley (1873), 11 Blatch. 317; 6 Fisher, 534; 5 O. G. 3.

That both Description and Claims are required in a specification, see Ex parte Crandall (1886), 35 O. G. 625.

That whether a Claim can also answer the purpose of a Description is doubtful, see Smith v. Murray (1886), 27 Fed. Rep. 69; 36 O. G. 1045.

2 In Ex parte Holt (1884), 29 O. G. 171, Dyrenforth, Act. Com.: (178) "The description of an invention by a specifi cation alone is not now, as formerly, all-sufficient; but the Description must be supplemented by a specific and welldefined Claim to the part, improvement, or combination which the inventor regards as his property. The aim, end, and purpose of the specification, under the present statute, is to describe the invention sought to be covered by the patent, and the manner of making, constructing and using the same. The aim, the end, the purpose of the Claim is to point out particularly and distinctly define the invention to be secured to the individual. The Claim is the measure of the patent, and the day has passed when the courts will search through the specification for information which it is the very office of the Claim to impart."

contains allusions to and delineations of many other arts or instruments besides the real invention, in order to enable the latter to be clearly understood, the Claim states the invention only, enumerating its essential characteristics and excluding everything for which the protection of the patent is not desired, with an implied or express reference to the Description for a fuller explanation of such features of the invention as the brevity of the Claim may leave obscure. The purposes of the two parts being thus distinct, their form and nature will be found to differ in a corresponding manner.

§ 483. The Description: its Object and General Requisites.

The Description is intended to render the invention accessible to the public. By this is meant that the knowledge of the invention communicated through the Description must be so complete and accurate that during the life of the patent the scope of the protected invention shall be clearly discernible, and that after the patent has expired the public can make it available for immediate practical use without the further exercise of inventive skill.1 A Description failing in any respect to accomplish this purpose is defective, and if the defect is incurable the patent based on the specification which embraces it is void.2 The rules which have been established by the statutes, the courts, and the Patent Office for securing this completeness and accuracy in the Descrip

fusion which would otherwise result by beginning the words with a capital letter whenever they are employed in their technical sense, as signifying parts of the specification.

§ 483. 1 In Parks v. Booth (1880), 102 U. S. 96, Clifford, J.: (101) "Inventors are required, before they secure a patent, to deliver a written Description of the improvement, and of the manner and process of making, constructing, and using the same, in such full, clear, and exact terms as to enable one skilled in the art or science to make, construct, and use the invention. Requirements of the kind may be regarded as conditions precedent to the

right of the Commissioner to grant such an application." 17 O. G. 1080 (1090).

See also Sullivan v. Redfield (1825), 1 Paine, 441; 1 Robb, 477.

That the patent, by its very terms, must confer a useful invention on the public, see Carr v. Rice (1856), 1 Fisher, 198; Opinion Atty. Gen. (1796), 1 Op. At. Gen. 64.

That the entire invention must be specified in the most unequivocal and unambiguous language, see Ex parte Williams (1876), 10 O. G. 748.

2 That an imperfect Description makes a patent void, see Wayne v. Holmes (1856), 1 Bond, 27; 2 Fisher, 20.

tion relate to its substance, or what it must contain, and to its form, or the mode in which what it contains must be expressed. These are now to be examined in detail in their order,

first, in reference to inventions in general; and second, in reference to each of the particular classes of inventions.

§ 484. The Description must Disclose the Attributes of the In

According to the statutes, the Description must contain full explanations of three different subjects: the invention itself; the manner of making it; and the mode of putting it to practical use, — a complete knowledge upon all these points being necessary to render the invention available to the public without further experiment or exercise of inventive skill. In describing the invention itself, each of its essential parts must be clearly and exactly delineated, and the relation of each to the others definitely portrayed.2 That some are to be found