The express terms of the clause no more require that the written references shall be incorporated in the specification than that the drawings shall be. If the references required are written on the drawings, the terms of the statute are satisfied. Hogg v. Emerson, 2 Blatch. 1; s. c. 6 How. 437; 11 How. 587; s. c. 2 Robb 655.

Unless references are necessary to an understanding of the invention, their omission cannot vitiate the patent. The description of the machine, accompanied by a drawing, may be in many cases understood without references. Brooks v. Bicknell, 3 McLean 250; s. c. 2 Robb 118; Washburn v. Gould, 3 Story 122; s. c. 2 Robb 206.

A drawing must be furnished when the case admits of it whether it is useful or necessary or not. Chase, 16 O. G. 809.

It is not necessary to use letters of reference to the drawing, in order to render a claim more definite. E. L. Parker, 3 Dec. Com. 293.

An applicant for a patent need not furnish a drawing of the whole of the machine which he claims to have improved, provided the machine is well known to the public, or a description of it readily accessible. Christopher C. Tracy, 8 O. G. 144; Edward J. Kemp, 15 O. G. 775.

Where the operation of the old parts of a machine is modified, controlled or unusually affected by the improvement, the drawing should show the whole machine. Edward J. Kemp, 15 O. G. 775.

If no novelty is claimed in a feature of an invention it need not be illustrated by drawings unless they are essential to such a description as will enable those skilled in the art to practice the invention. Carter, 16 O. G. 809; Edward J. Kemp, 15 O. G. 775.

It is not necessary for the applicant to illustrate by drawings the several steps in each stage of a sub-process. Carter, 16 0. G. 809.

If the claim is for a combination the drawing should show the parts combined. Edward J. Kemp, 15 O. G. 775 ; Rulof Dodge, 2 Dec. Com. 149.

SEC. 4890. When the invention or discovery is of a composition of matter, the applicant, if required by the commissioner, shall furnish specimens of ingredients and of the composition, sufficient in quantity for the purpose of experiment.

Statute Revised-July 8, 1870, ch. 230, § 28, 16 Stat. 201.

Prior Statutes-February 21, 1793, ch. 11, § 3, 1 Stat. 321.-July 4, 1836, ch. 357, § 6, 5 Stat. 119.

If the specification for a composition clearly describes the composition and all the ingredients and proportions in language perfectly intelligible to those skilled in the art, the patent will not be invalidated by a failure to deposit a sample of the ingredients in the patent office. This requirement, like some others, is made obligatory before the granting of the patent. It is for the commissioner to decide before granting the patent, whether it has been complied with. If he does so decide and grants the patent, that can not be subsequently impeached by evidence tending to

show want of compliance with the law as to giving notice or paying fees or performing the other acts required to be done before the patent is granted, and the performance of which is to be proved to the satisfaction of the commissioner, whose decision on these questions is final where he has jurisdiction. Tarr v. Folsom, 1 Holmes 312; s. c. 5 O. G. 92; s. c. 1 Ban & Ard. 94; Anilin Fabrik v. Cochrane, 16 Blatch. 155; s. c. 4 Ban & Ard. 215.

SEC. 4891. In all cases which admit of representation by model, the applicant, if required by the commissioner, shall furnish a model of convenient size to exhibit advantageously the several parts of his invention or discovery.

Statute Revised-July 8, 1870, ch. 230, § 29, 16 Stat. 201.

Prior Statutes-April 10, 1790, ch. 7, § 2, 1 Stat. 110.-February 21, 1793, ch. 11, § 3, 1 Stat. 321.-July 4, 1836, ch. 357, § 6, 5 Stat. 119.

A model will be required in every case when the nature of the invention admits of such illustration, except the applications upon designs. John Murdock, 6 O. G. 506.

A model will not be required unless it is useful as an aid in examining into the state of the art or in the construction of the specification and drawing. Jove, 17 O. G. 801.

As the purpose of the model is to assist in the reading of the drawing, the model must correspond with the drawing and specification. James W. Schoonmaker, 13 O. G. 595.

An applicant for a patent for an improvement on a machine need not furnish a model of the whole machine if it is well known to the public or a description of it is readily accessible. Christopher C. Tracy, 8 O. G. 144; Edward J. Kemp, 15 O. G. 775.

An applicant for a patent for a combination must furnish a model. Rulof Dodge, 2 Dec. Com. 149.

SEC. 4892. The applicant shall make oath that he does verily believe himself to be the original and first inventor or discoverer of the art, machine, manufacture, composition, or improvement for which he solicits a patent; that he does not know and does not believe that the same was ever before known or used; and shall state of what country he is a citizen. Such oath may be made before any person within the United States, authorized by law to administer oaths, or when the applicant resides in a foreign country, before any minister, chargé d'affaires, consul, or commercial agent, holding commission under

the government of the United States, or before any notary public of the foreign country in which the applicant may be.

Statute Revised-July 8, 1870, ch. 230, § 30, 16 Stat. 202.

Prior Statutes-February 21, 1793, ch. 11, § 3, 1 Stat. 321.-July 4, 1836, ch. 357, § 6, 5 Stat. 119.-August 29, 1842, ch. 263, 4, 5 Stat. 544.

The taking of the oath that the patentee is the true inventor or discoverer of the art, machine, or improvement, is but a prerequisite to the granting of the patent, and in no degree essential to its validity. It is not a condition precedent without which the patent fails. Whittemore v. Cutter, 1 Gallis. 429; s. c. 1 Robb 28; Crompton v. Belknap Mills, 3 Fish. 536; Dyer v. Rich, 42 Mass. 180; contra, Child v. Adams, 1 Fish. 189; s. c. 3 Wall. Jr. 20.

The mere presence of a blank form of the oath, with the jurat not signed by any magistrate, on file in the case in the Patent Office, can not overcome the direct recital of the letters patent that the oath was taken. Crompton v. Belknap Mills, 3 Fish. 536.

The recital in the patent that the required oath was taken before the same was granted is, in the absence of fraud, conclusive evidence that the necessary oaths were so taken. Seymour v. Osborne, 3 Fish. 555; s. c. 11 Wall. 516.

The oath may be taken elsewhere than before the commissioner. Seymour v. Osborne, 3 Fish. 555; s. c. 11 Wall. 516.

If the inventor signs the petition in which he declares himself to be the inventor, but omits to sign the affidavit, it is for the department to determine whether the necessary oath is shown or not, and its decision upon that question is final. De Florez v. Reynolds, 14 Blatch. 505; s. c. 3 Ban & Ard. 292.

There is no provision which requires that the jurat to the application shall be dated, and consequently the omission of the date of the day or month does not affect the validity of the patent. French v. Rogers, 1 Fish. 133.

If an application is amended after the death of the inventor, so as to embrace an invention different from that shown in the original application, without any additional oath by his administrator or executor, the patent is void. Eagleton Manuf. Co. v. W. B. & C. Manuf. Co., 17 O. G. 1504; s. c. 18 Blatch. 218; s. c. 5 Ban & Ard. 475; s. c. 2 Fed. Rep. 774.

An applicant may be required to make oath that the invention has not been in public use in this country for more than two years prior to his application. Rowan, 22 O. G. 1037.

An applicant can not be required to make oath that the invention was not known or used prior to his application. Rowan, 22 O. G. 1037.

The oath of an applicant is not a mere formal matter, but is required by act of Congress, because it goes to assure the novelty and utility of the invention. Eaton, Blodgett & Mills, 4 O. G. 525.

The objection that a specification was made out on papers signed and sworn to in blank will be waived if a specification properly described and sworn to is substituted. De La Mar v. Gaurens & Behrens, 1 Dec. Com. 94.

A new oath must accompany the divisional portion of an application the same as if it were an original application. James Heginbotham, 8 0. G. 237.

An affidavit taken before a burgomaster is not sufficient. Warnant v. Warnant, 17 O. G. 265.

If the affidavit was not taken before the proper officer, the omission is not supplied by an affidavit to a preliminary statement. Warnant v. Warnant, 17 O. G. 265.

SEC. 4893. On the filing of any such application and the payment of the fees required by law, the commissioner of patents shall cause an examination to be made of the alleged new invention or discovery; and if on such examination it shall appear that the claimant is justly entitled to a patent under the law, and that the same is sufficiently useful and important, the commissioner shall issue a patent therefor.

Statute Revised-July 8, 1870, ch. 230, § 31, 16 Stat. 202.

Prior Statutes-April 10, 1790, ch. 7, § 1, 1 Stat. 109.-July 4, 1836, ch. 357, § 7, 5 Stat. 119.

The commissioner is required to cause an examination to be made of the alleged invention or discovery, but he is not specifically told by what particular officers he is to have the examination made. Hull v. Commissioner, 7 O. G. 559; s. c. 8 O. G. 46; s. c. 2 McArthur 90, 125.

The commissioner is not bound to issue the patent, although the examiners in chief decide in favor of the applicant; but he may examine the evidence and withhold the patent. Hull v. Commissioner, 7 O. G. 559; s. c. 80. G. 46; s. c. 2 McArthur 90, 125.

The commissioner, with the approval of the Secretary of the Interior, has the power to institute proceedings for the purpose of inquiring into allegations of a public use or sale of an invention more than two years prior to the application for a patent. In re Alteneck, 23 O. G. 269.

If the commissioner investigates allegations in regard to a public use or sale of the invention more than two years prior to the application for a patent, he must give the applicant an opportunity to cross-examine the witness. In re Alteneck, 23 O. G. 269.

A protest against the issuing of letters patent for a certain device will not be considered, unless it is accompanied with legitimate proof showing presumptively that the application against which the protest is directed has been or is about to be filed. Neale, 15 O. G. 511.

If an assignment is not sufficient to warrant the grant of a patent to the assignee, either as sole or joint grantee, it is not sufficient to entitle him to appear in proceedings upon the application. Hammond v. Pratt, 16 O. G. 1235.

A parol assignment is not sufficient to entitle the party to appear and assert the right to become a joint patentee or to conduct the application in place of the inventor. Hammond v. Pratt, 16 O. G. 1235.

The issuing of all patents is at the control of the commissioner, and he may stop any one for good cause, although the examiners in chief have decided on appeal that it ought to issue. Stephen Hull, 1 Dec. Com. 68; Moody v. Hudson, 1 Dec. Com. 108; Morris & Watson, 2 Dec. Com. 71.

The commissioner will not arrest the issue of a patent allowed by the examiners in chief, except in cases in which it is beyond question that their judgment is erroneous or opposed to the general policy of the patent office. Disston v. Traut, 1 O. G. 305.

The commissioner can not ignore an objection to patentability whenever his attention is called to it by the examiner in chief or the primary examiner, although the objection may be made in an irregular manner. William S. Smoot, 11 O. G. 1010.

If there is an allegation that the invention has been in use for more than two years prior to the application, the commissioner may refer the case to the examiner of interferences, with direction to provide for taking evidence. Frederick Alteneck, 23 O. G. 2233.

If the commissioner discovers that there is no novelty in a patent before he affixes the seal of the office to it, he may withhold it, although it has been signed by the commissioner and the Secretary of the Interior. Franklin B. Hunt, 13 O. G. 771.

When the commissioner deems it improper to complete the issue of a patent after it has been signed. he should transmit the same to the Secretary of the Interior with all the papers in the case before taking any further action thereon, with his reasons for declining to complete the issue. Franklin B. Hunt, 13 O. G. 771.

SEC. 4894. All applications for patents shall be completed and prepared for examination within two years after the filing of the application, and in default thereof, or upon failure of the applicant to prosecute the same within two years after any action therein, of which notice shall have been given to the applicant, they shall be regarded as abandoned by the parties thereto, unless it be shown to the satisfaction of the commissioner of patents that such delay was unavoidable.

Statute Revised-July 8, 1870, ch. 230, § 32, 16 Stat. 202.
Prior Statute-March 2, 1861, ch. 88, § 12, 12 Stat. 248.

The statute does not interpose an absolute bar to the granting of a patent where the application has not been completed and prepared for examination within two years. The delay may be condoned by proof that it was unavoidable. The decision of the fact is committed to the