inventions to which the patent sought to be extended belonged, and having received the report of the examiner, to hear and decide each particular case at the time and place designated in the advertisement. All these provisions were directory, and none of them were jurisdictional. The validity of no extension could therefore be affected by proof, in an infringement suit, that some or all of those acts were omitted by the Commissioner, or were irregularly performed.'

§ 269. No fraud, practised upon or by the Commissioner, relevant to securing or granting an extension, can ever become the subject of inquiry in any suit for infringement. The decision of the Commissioner, in granting an extension, does not, however, foreclose all inquiry into allegations of fraud, as it does into allegations of inadvertence, error, or ministerial irregularity. The law is not so absurd as to make a man's own decision that he has committed no fraud, and suffered none to be committed upon him, a conclusive adjudication of that point. But charges so grave deserve a special proceeding for their investigation. They are not to be bandied about as collateral makeweights in infringement suits. When investigated, they must be investigated in a special proceeding brought to repeal the grant of the extension.2

$270. "The benefit of the extension of a patent shall extend to the assignees and grantees of the right to use the thing patented, to the extent of their interest therein."" This enactment, in almost precisely the same words, has always found a place in statutes relevant to extensions of patents. The meaning of this law was never learned from its perusal. It is one of the cases in which persons who could neither think nor write with precision or with clearness, were put to penning statutes for a nation. It is an

Brooks v. Jenkins, 3 McClean, 435, 1844; Colt v. Young, 2 Blatch. 473, 1852; Tilghman v. Mitchell, 9 Blatch. 27, 1871.

Rubber Co. v. Goodyear, 9 Wal

lace, 796, 1869; Mowry v. Whitney, 14 Wallace, 434, 1871.

3 Revised Statutes, Section 4928. 4 Patent Act of 1836, Section 18; Patent Act of 1870, Section 67.

instance in which Congress made a law for millions, without having any accurate idea of the nature of the law it was making. The duty of ascribing a definite meaning to the enactment, devolved, therefore, upon the courts. But the clause was so ambiguous that the judges could not agree in regard to it. A provision which should have been put beyond question by a competent and faithful Congress, when it was enacted in 1836, was still a subject of controversy in the Supreme Court more than thirty-seven years later. Now that more than fifty years have passed since its enactment, the text writer can collate the adjudicated cases, and can deduce and state the adjudicated meaning of the clause. That meaning is as follows.

§ 271. Every person who, at the beginning of any extended term of any patent, has a right to use a particular specimen of any thing covered by that patent, has the same right to use that specimen during that extended term, unless his right was expressly limited so as not to include that term; and if such a person is the owner of such a specimen, he may sell it to be used by others during that extension.'

The limitations expressed in this rule are not to be overlooked. 1. It applies only to persons whose right to use existed at the time of the extension. It has therefore been the practice of some patentees to avoid the rule altogether, by making their licenses expire a day or more before the end of the existing terms of their respective patents. 2. The rule confers no right upon any person on account of his having had a right to make or sell specimens of the patented thing. 3. The rule does not apply to any patent for a process.' 4. The rule confers no right under an extension, that

1 Wilson v. Rousseau, 4 Howard, 677, 1846; Bloomer v. McQuewan, 14 Howard, 539, 1852; Chaffee v. Belting Co. 22 Howard, 217, 1859; Bloomer v. Millinger, 1 Wallace, 340, 1863; Mitchell v. Hawley, 16 Wallace, 544, 1872; Eunson v. Dodge, 18 Wallace, 414, 1873; PaperBag Cases, 105 U. S. 766, 1881;

Woodworth v. Curtis, 2 Woodbury and Minot, 524, 1847; Goodyear v. Rubber Co. 1 Clif. 349, 1859; Wooster v. Sidenberg, 13 Blatch. 88, 1875; Black v. Hubbard, Bann. & Ard. 39, 1877.

Wetherill v. Zinc Co. 6 Fisher,

50, 1872.

2

did not exist under the former term. Accordingly, if the former right was subject to a royalty, the right under the extension will be subject to the same royalty.' 5. The rule confers no right to make or use or sell any new specimen of the patented thing; though it does confer a right to repair the articles to which it applies. 6. The rule does not apply where the right to use, when granted by the patentee, was expressly limited to the existing term of the patent. right provided by the rule of this section is a property right; and the specimens to which it refers, and the right to use those specimens, may therefore be transferred by sale, devise, levy of execution, or assignment in insolvency.'

Union Mfg. Co. v. Lounsbury,

41 New York, 363, 1869.

Hodge v. Railroad Co. 6 Blatch. 185, 1868; Wood v. Railroad Co. 2 Bissell, 62, 1868.

3 Wilson v. Simpson, 9 Howard, 109, 1850; Aiken v. Print Works, 2

The

Clif. 435, 1865; Farrington v. Detroit, 4 Fisher, 216, 1870.

4 Mitchell v. Hawley, 16 Wallace, 544, 1872.

5 Woodworth v. Curtis, 2 Woodbury and Minot, 524, 1847.

§ 272. TITLES to patent rights are capable of two independent classifications. One relates to the nature of title; and the other relates to the methods by which title may be acquired. In the first of these aspects, titles are divisible into those which are purely legal, those which are purely equitable, and those which are both legal and equitable. In the second aspect, they are divisible into those: 1. By occupancy. 2. By assignment. 3. By grant. 4. By creditor's bill. 5. By bankruptcy. 6. By death. Titles which are both legal and equitable may be acquired in either of these methods. Titles which are purely equitable may be acquired by either, except the first; and those which are purely legal may be transferred by either, except the first, fourth and fifth. It is the plan of this chapter, to treat the subject of title under this sixfold division; and, in general, to treat it with a view to title which is both legal and equitable, and is therefore complete; but also, to incorporate

into that treatment, such statements as may show the relations which purely legal and purely equitable titles bear to each other, and to the law; and to conclude the whole with a discussion of such points as relate to patent rights owned contemporaneously by a plurality of persons.

§ 273. Title by occupancy is that title to a patent, which a person may acquire by inventing any new and useful process, machine, manufacture, or composition of matter, and by applying for and obtaining a patent thereon. During the space of time between the day of invention and the date of letters patent therefor, that title is inchoate, but is nevertheless recognized by both law and equity.' Such an inchoate right may be assigned; and an assignment thereof will convey the legal title to the letters patent, as soon as the letters patent are granted.' This rule applies not only to cases where the assignments are recorded before the granting of the patents, but also to cases where, though executed before, they are not recorded till after that event.* So also it applies to cases where applications are divided after they are assigned,' and to cases where the assignments are executed after applications for patents are rejected, and before those rejections are reversed. The inchoate right to a Patent Office extension of a patent, when such a right was provided by law,' was also a proper subject of assignment, even while it remained inchoate; and such an assignment also operated to convey the legal title to such an extension, whenever such an extension was granted by the Commissioner of Patents.'

The title by occupancy, which an inventor acquires when