53. This last section has been modified by the act of March 3, 1837, which enacts as follows: Section 9, That anything in the fifteenth section of the act to which this is additional to the contrary notwithstanding That, whenever by mistake, accident, or inadvertence, and without any wilful default or intent to defraud or mislead the public, any patentee shall have in his specification claimed to be the original and first inventor or discoverer of any material or substantial part of the thing patented, of which he was not the first and original inventor, and shall have no legal or just right to claim the same in every such, case the patent shall be deemed good and valid for so much of the invention or discovery as shall be truly and bona fide his own: Provided, it shall be a material and substantial part of the thing patented, and be definitely distinguishable from the other parts so claimed without right as aforesaid. And every such patentee, his executors, administrators and assigns, whether of the whole or of a sectional interest therein, shall be entitled to maintain a suit at law or in equity on such patent for any infringement of such part of the invention or, discovery as shall be bona fide his own as aforesaid, notwithstanding the specification may embrace more than he shall have any legal right to claim. But, in every such case in which a judgment or verdict shall be rendered for the plaintiff he shall not be entitled to recover costs against the defendant, unless he shall have entered at the patent office, prior to the commencement of the suit, a disclaimer of all that part of the thing patented which were so claimed without right: Provided, however, That no person bringing any such suit shall be entitled to the benefits of the provisions contained in this section, who shall have unreasonably neglected or delayed to enter at the patent office a disclaimer as aforesaid. See Bac. Ab. Monopoly Id. Prerogative, F 4; Phill. on Pat.; Fessend. on Pat.; Carpm. on Pat.; Hand on Pat.; Webst. on Pat; Coll. on Pat.; Gods. on Pat.; Holr. on Pat.; Smith on Pat.; Drewry's Patent Law Abandonment Act; Davies' Collection of Cases on the Law of Patents; Rankin's Analysis of the Law of Patents. Among the French writers are Perpigna on Patents; written in English'; and the Manuel of the same author, in French; and the works of Renouard, Dalloz, Molard, and Regnault. See the various Digests h. t. and particularly Peters' Digest, h. t.

PATENT FRENCH. The following points in relation to the patent laws of France will be found useful to those who have invented valuable machinery, and who are desirous of availing themselves of the patent laws of that country: -

27 - §1. To whom patents are granted. All persons may obtain patents in this country, whether they are men or women, adults or infants, Frenchmen or foreigners, and in general all persons who fulfil the conditions required by the law in order to obtain patents.

3. It is not requisite that the applicant should be present, but the application must be made in his name.

4. - §2. The different kinds of patents. There are three principal kinds of patents. 1. Patents for inventions, (brevets d' invention.) 2. Patents for improvements, (brevets de perfectionnement.) 3. Patents for importa tions, (brevets d'importations.) But as patents may be taken for a combination of the above, there may be added, by such combination, four others, namely; 5. Patents for invention and improvements, (brevets d'invention et de perfectionnemen t.) 6. Patents for invention and importation, (brevets d'invention et d'importation.) 7. Patents for importation and improvement, (brevets d'importation et de perfectionnement.) 8. Patents for importation, invention and improvement (brevets d'invention, et perfectionnement et d' importation.)

5. The forms prescribed to obtain these several kinds of patents are exactly, the same, the only difference consists in the declaration of the applicant, which must be in conformity with the kind of patent he desires to obtain.

6. The applicant himself has the right to fix the number of years for, which he desires to have his patent, when he applies, to have his request registered at the prefecture. He may ha ve it for five, ten, or fifteen years. And this period he has a right to change until the patent has been signed. But with regard to patents for importations, the duration of the patent cannot extend beyond the period for which there is a patent in the country, from which the importation has been made.

7. Patents, other than for importation, may be extended as to time. There are two species of prolongation; the first, within fifteen years; the second, beyond fifteen years.

8. - §3. Cost of patents. The tax, as it is called, which must be paid in order to obtain a patent, varies according to the duration of the patent. This tax may be paid in cash or by instalments. When paid in cash, it is as follows: 1. For, five years, 300 francs, about 56 dollars and 40 cents. 2. For ten years, 800 francs, about 94 dollars. 3. For fifteen years, 1500 francs, about 282 dollars; besides some office expenses, amounting to from ten to fifteen dollars.

9. - §4. Foreign patents. The patentee in France cannot obtain a patent in a foreign country, without losing his rights in France; but this provision is easily eluded by anotber person taking out the patent in the foreign country, when patents for importations are granted. Perpigna, Manuel des Inventeurs, &o., c. 3, 5, p. 90.