The difference in the jurisprudence of the two countries in this respect, is not in the general rules of interpretation and construction of grants or written instruments, for these do not differ; the English courts apply the same principles of construction that ours would apply; but as one of these rules is, that in construing any document, the whole is to be considered, and each part interpreted accordingly, the difference consists in the title constituting the whole instrument in the English patents, whereas ours embraces the specification. These very cases, some of which would have been differently decided in the United States, may, therefore, be authorities in our courts for the construction of written instruments.

It is a general rule in construing written instruments that other documents referred to in them must be taken into consideration. Thus the drawings annexed to a specification in compliance with the statute, are considered to be a part of the specification, and so to be taken into consideration, in putting a construction upon it."

The English cases furnish some examples of another rule of construction common to specifications and other writings, namely, that where definite

12 Earle v. Sawyer, 4 Mason's R. 9. In this case, Mr. Justice Story considers Lord Eldon's remarks on drawings or pictures as he calls them, in Fox ex parte, 1 Ves. and B. 67, to be in accordance with the above rule of construction.

and specific, and also very general descriptive terms are used in reference to the same subject matter, the meaning of the latter may be modified and restrained by the former. This is illustrated in the case of a patent for "an apparatus for extracting inflammable gas by heat, from pit-coal, tar, or any other substance, from which gas or gasses, capable of being employed for illumination, can be extracted by heat." It was proved that the apparatus would not succeed in making gas from oil, and it was objected to the patent that there was nothing to prevent a person, who saw the specification, from considering that it was meant to be included, and so that the specification covered more ground than the invention, and was not true, and that accordingly, the patent was void. But Lord Tenterden ruled that the phrase "any other substance" must be construed to be applicable to substances of the same sort, (ejusdem generis), with those enumerated, and so that the description was sufficiently accurate, and the patent valid.

Though words are used in an unusual sense, yet this will be no ground of objection, if the patent or specification itself, or the customary technical phraseology of the art to which the patent relates, furnishes an explanation. In the cases relating to Watt's patent, there was much discussion on the

construction of words used in the patent, and in the specification. It was held, as we have seen, that an engine might be described as a method of lessening the consumption of fuel and steam in fire-engines. In the specification, the invention was said to consist of the following principles, and the patentee then proceeded to describe the machinery and apparatus for which he claimed a patent, thus defining what he meant by principles, and though the word was thus used in an unusual sense, and inaccurately, yet as the sense in which it was used was apparent from the specification, this was held to be no ground of objection. So Lord Ellenborough remarked, in another case, that if a term used in the specification had a meaning annexed to it by the usage of trade, different from its ordinary use, it might be received in the peculiar perverted sense.15

14

Technical words are often used in patents and specifications, and sometimes it is not practicable to describe an invention without the use of them. And it has been held that words of a foreign language and figures may be introduced into the specification.16

A mistake in the use of one word for another, so as either to pervert the sense, or make nonsense, may be rectified in the case of a patent as well as in

14 Boulton v. Bull, 2 H. Bl. 463; Hornblower v. Boulton, 8 T. R. 95. And see Jones v. Pearce, Gods. sup. 16.

15 The King v. Metcalf, 2 Stark, N. P. 249.

16 Bloxam v. Elsee, 1 Car. & P. 558.

other written instruments, by other parts of the document. Thus, where the word painting was used by mistake in the patent for the word printing, Mr. Justice Washington held that the error might be corrected by other parts of the patent and the specification.17

CHAPTER XI.

Specification.

Sec. 1. Leading Objects in the Specification. Distinction between English and American Patents

as to the Specification.

2. General Requisites.

3. Known Processes, Methods and Machinery need not be described. Surplusage.

4. The Specification is addressed to Artists. Technical Terms.

5. Must be true and not mislead.

6. Must be full, clear, and exact.

7. What is claimed as new must be distinguished from what is old. The Patentee must not claim too much.

17 Kneass v. Schuylkill Bank, C. C. U. S. Penn. Oct. 1820, Coxe's Dig. 532.

8. The Specification must direct how to make, and describe the best way known to the Inventor of making the article.

9. Reference in the Specification to Drawings. 10. The consequence of a defect in the Specification.

Sect. I.-LEADING OBJECTS IN THE SPECIFICATION. DISTINCTION BETWEEN ENGLISH AND AMERICAN PATENTS AS TO THE SPECIFICATION.

THE specification is no less important than the invention itself, and the instances of patents being declared void by the courts on account of the defects of the specification, are probably quite as many as those of failure from the insufficiency of the invention. It requires no little skill and knowledge of the subject of the invention, to draw up an adequate and apt specification. And skill and knowledge of the subject will not suffice for this purpose, without also a knowledge of the law of patents generally.

The frequent failure of patents in consequence of defects in the specification through inadvertency, has heretofore been a subject of loud complaint, both in England and the United States, until the legislatures of both countries, that of the United States in 1832, and that of Great Britain in 1835, passed laws to remedy this evil. These provisions have been mentioned above,' and will be more particularly stated in a subsequent section of the present chapter.2