PATENT. 



433 



obtained for a method or process by which something 

 new or beneficial is done, when it is connected with 

 corporeal substances, and is carried into effect by 

 tangible means, as in the case of Watt's steam-en- 

 gine, which was described to be a method of lessen- 

 ing the consumption of fuel in a steam-engine. So 

 a chemical discovery, when it gives to the commu- 

 nity some new, vendible, and beneficial substance, or 

 compound article, is a subject of a patent, as medi- 

 cines, &c. But a patent for a mere curiosity is void. 

 If the manufacture in its new state merely answers 

 as well as before, the alteration is not the subject of 

 a patent : nor is a mere philosophical abstract prin- 

 ciple, nor the application or practice of a principle, 

 the subject of a patent. No patent can be obtained 

 for the expansive operation of steam ; but only for 

 a new mode or application of machinery in employ- 

 ing it. 



Right how lost. The inventor may lose his right 

 to a patent by using, or allowing others to use, his 

 invention publicly. It was considered that Dr Hall 

 had not lost the right to a patent for his discovery of 

 the object-glasses, because he had not made it known 

 to others, though it was not-immediately patented. 

 If the secret of an invention is known only to a few 

 persons, and one of them puts it in practice, then a 

 patent afterwards obtained by any one of them is void. 

 This happened to Mr Tennant, because a bleacher, 

 who had not divulged the secret to any other person 

 but his two servants, had used the same kind of 

 bleaching-liquor for several years anterior to the date 

 of Tennant's patent. Where a person who sought 

 a patent for making spectacles incautiously told an 

 acquaintance of the principle of the invention, by 

 which means a person of the same trade made a 

 similar pair, and the inventor, seeing them in a 

 shop window, employed a friend to purchase them 

 for him, and the patent was afterwards granted, it 

 was said to be secure. The question does not, how- 

 ever, appear to have been brought before a court, 

 and Mr Godson thinks that the patent was void. A 

 patent for British imperial verdigris was declared to 

 be void, because the inventor had, four months prior 

 to the sealing of the grant, sold the article under a 

 different name. Whether experiments made with a 

 view to try the efficacy of an invention, or the ex- 

 tent of a discovery, are a using, and dedicating the 

 invention to the public, within the statute of James, 

 has not been decided ; but it would be difficult to 

 say how much a substance or machine might be 

 used without running great risk of invalidating the 

 right to a patent. In France, if the inventor do not, 

 within two years, put his discovery into activity, or 

 do not justify his inaction, the patent is annulled. 



Duration of the Patent. In England and the 

 United States of America, patents are granted for a 

 term not exceeding fourteen years. The time in 

 England may be prolonged by a private act, and, in 

 the United States of America, by act of congress. 

 In France, by the law already mentioned, patents 

 are given for five, ten, or fifteen years, at the option 

 of the inventor ; but this last term is never to be 

 prolonged without a particular decree of the legisla- 

 ture. The duration for imported discoveries is not 

 to extend beyond the term fixed for the privilege of 

 the original inventor in his own country. In France, 

 if the inventor obtains a patent in a foreign country 

 after having obtained one in France, the patent is 

 annulled. Caveat. In England, a caveat is an in- 

 strument by which notice is requested to be given 

 to the person who enters it, whenever any applica- 

 tion is made for a patent for a certain invention, 

 which is therein described in general terms. It must 

 be renewed annually. It is simply a request that, if 

 any other person should apply for a patent for the 



same thing, the preference may be given to him who 

 entered it. In the United States of America, in case 

 of interfering applications for a patent, they are sub- 

 mitted to the arbitration of three persons, appointed 

 one by each applicant, and one by the secretary of 

 state. 



Specification. The invention for which a patent 

 is granted must be accurately ascertained, and par- 

 ticularly described. The disclosure of the secret is 

 the price of the monopoly. The specification must 

 be such, that mechanics may be able to make the 

 machine by following the directions of the specifica- 

 tion, without any nesv inventions of their own. The 

 patent and specification are linked together by the 

 title given to the invention in the patent, and the 

 description of it in the specification. The specifica- 

 tion must support the title of the patent: thus a 

 patent taken out for a tapering brush is not sup- 

 ported by the specification of a brush in which the 

 bristles are of unequal lengths. It must point out 

 what parts are new and what old. It must not cover 

 too much : if ft does so, it is not effectual, even to 

 the extent to which the patentee would be otherwise 

 entitled ; as, if there be a patent for a machine and 

 for an improvement upon it, which cannot be sus- 

 tained for the machine, although the improvement is 

 new and useful, yet the grant altogether is invalid, 

 on account of its attempting to cover too much. A 

 patent for a new method of drying and preparing 

 malt is not sustained by a specification in which is 

 described a method for heating, &c., ready-made 

 malt : so a patent for an invention founded on a 

 principle already known, for lifting fuel into the 

 fire-grate from below the grate, in the specification 

 whereof was described a new apparatus, was held 

 to be bad for not claiming the new instrument as the 

 thing invented : so when a patent was " for a new 

 method of completely lighting cities, towns, and vil- 

 lages," and the specification described improvements 

 upon lamps, the patent was held to be void. The 

 subject must be given to the public in the most im- 

 proved state known to the inventor. A patent, in 

 England, for steel-trasses, was held to be void, be 

 cause the inventor omitted to mention that, in tem- 

 pering the steel, he rubbed it with tallow, which 

 was of some use in the operation. The specification 

 must not contain a description of more than the 

 improvement or addition. If there be several things 

 specified that may be produced, and one of them is 

 not new, the whole patent is void. In England, if 

 any considerable part of a manufacture be unneces- 

 sary to produce the desired effect, it will be pre- 

 sumed that it was inserted with a view to perplex 

 and embarrass the inquirer : thus, in 1 Term Re- 

 ports, 602, in Turner's patent for producing a yel- 

 low colour, among other things, minium is directed 

 to be used, which, it appeared, would not produce 

 the desired effect, and, for this reason, the validity of 

 the patent might be impeached. In the specifica- 

 tion of Winter's patent, 1 Term Reports, 602, a 

 great number of salts were mentioned, by which it 

 appeared that either might be used to make the sub- 

 ject of the patent, but only one would, in fact, pro- 

 duce the effect ; and, for this reason, the patent was 

 held to be void. If the patentee makes the article 

 of cheaper materials than those which he has enu- 

 merated in his specification, although the latter an- 

 swer equally as well, the patent is void. In Eng- 

 land, if the improved manner of using the invention 

 be unintentionally left undescribed, still the patent is 

 void. (I Mason's Reports, 189.) In France, the 

 general rules, in these respects, are similar. 



Enrolment. In England, a patent is void unless 

 it is enrolled. The time allowed for the enrolment 

 is now generally confined to one month. Enrolment 



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