produced. The Court said, it should have shown by what degree of heat the effect was to be produced. Fusion was not mentioned; indeed, by mentioning calcination, it seemed that fusion was to be avoided.(u) The patent was held bad. The specification of a patent for making seidlitz powders gave three distinct recipes for preparing the ingredients being three common processes for preparing well-known substances, which might have been procured in any chemist's shop. Abbott, C.J., said, people were led to suppose a laborious process necessary to the production of common things. The public were misled by the specification.(v) 37. The patentee is bound to give to the public the most improved state of his invention. If he can make the article with cheaper or better materials than those specified, his patent is void, because he does not enable the public to derive the same benefit that he himself does. (w) If he withholds any information that is of importance, his patent is avoided. Zinck had a patent for making verdigris. He was accustomed to put aquafortis into his boiler, but did not mention it in his specification. The aquafortis enabled him to make the verdigris with less labour. Gibbs, C.J., said it was a prejudicial concealment. (a) If in the description of the mode of carrying out the invention, things are mentioned which are unnecessary, if they are thrown in for the purpose of puzzling people who read the specification, the patent is void.(y) In making steel trusses, the patentee was in the habit of using tallow in tempering the steel. Having omitted to state it in the specification, his patent was held void.(z) The omitting to mention anything which the patentee knows to be useful, though it relates only to the degree of utility, as partitions in a cylinder for heating air for a hotblast furnace, will be fatal to a patent.(a) 38. If the application of a principle is claimed, the speci (u) Turner v. Winter, Dav. P. C. 145; Galloway v. Bleadon, Webst. P. C. 524, Tindal, C.J. (v) Savory v. Price, Ryan & Moody, 1. (w) Turner v. Winter, Dav. P. C. 154; S. C. Webst. P. C. 81. Rex v. Arkwright, Davies's Pat. Ca. 118; Webst. P. C. 69. per Alderson, B. Webst. P. C. 174. (a) Neilson v. Harford, Webst. P. C. 337. fication must point out at least one mode in which the invention can be carried into effect. If that is done, and the patentee honestly discloses the best mode with which he is acquainted, and the apparatus so constructed is of some value, the specification is sufficient. The greatest improvements subsequently made will not affect its validity. The specification of a patent for the application of the hot blast to furnaces, the air under blast being heated at a particular stage of the process, not claiming any as the best contrivance for heating the air, but merely pointing out one which was stated not to be material to the useful effect, was held to be good, though it turned out afterwards, that this form was very inferior to those which persons in the trade, using the invention, ultimately adopted. The only question for the jury was held to be-will any contrivance which heats the blast produce that beneficial effect? Supposing the mode described not to be perfect in its details (in the case above mentioned the hot blast had a tendency to destroy the furnace, and the old dry twires in use at the time of its adoption), the question is, does the evidence show that without improvement the invention, as described, is of no practical utility?(b) 39. If the patentee knows that any particular substance will not answer, he should say so, and not leave it to be inferred that it may be used. A patentee stated, that a cloth for conducting paper might be made of any suitable material, but that he preferred it made of linen warp and woollen weft, knowing at the time that no other cloth would answer. The patent was held void. (c) 40. The specification must embrace all the patentee's discoveries and improvements in the mode of carrying the invention into effect, up to the day of completing the specification.(d) Time is allowed that the patentee may make experiments, and have an opportunity of calling to his assistance the knowledge of others on points where his learning or practice falls short. If a person, at the time of applying for a patent, has in his (b) The Househill Company v. Neilson, L. J. C. Hope, Webst. P. C. 694, 696. (c) Crompton v. Ibbotson, Danson & Lloyd, 33; Webst. P. C. 83. (d) Jones v. Heaton, Webst. P. L. 137; Webst. P. C. 404, n. per Lord Mansfield. See Webst. P. C. 54, note e. mind an invention capable of producing the proposed effect, and has brought it to a great degree of perfection, and afterwards, within the time allowed by the specification, renders it more complete by the introduction of improved mechanical contrivances for carrying into effect the same principle in parts of his machine, that will not make the patent void. Not only is he at liberty to introduce these improvements into his specification, but it is his bounden duty to do so. A patent was obtained for a gas-meter. After the grant of the patent, and during the interval allowed for specifying, the patentee made an improvement in the manner of sealing the ends of the induction and eduction pipes, by buckets and hoods. The meter was merely rendered more complete by the introduction of improved machinery. It was held that the patentee was right in specifying this improvement. No deception was practised on the Crown because the inventor had discovered, and the intention of the Crown was to grant a patent for an improved gas apparatus. (e) We have already seen that no distinct substantive invention, made subsequently to the grant of the patent, can be included. 41. The mode of operation must be ascertained with the greatest degree of precision that the subject reasonably admits of. A specification for the composition of a medicine, must state the proportions of the drugs employed. That of Dr. James's powder, for fevers, mentioned only the articles of which the powders were composed, and omitted to mention the relative proportions and quantity. No patent could stand on such a specification.(ƒ) If a patent is for a particular combination of ingredients already in use, the relative proportions and quantities should be ascertained.(g) 42. If the patent is for a process, a certain and precise process must be described. It will be bad if it does not state for what length of time the process is to be continued, or give some other criterion for ascertaining when, or by what intensity of operation, the effect intended will be produced.(h) (e) Crossley v. Beverley, Webst. P. C. 118, at Nisi Prius. James's patent, per Lord Mansfield, cited Webst. P. C. 54, note e. (g) Hill v. Thompson, 8 Taunt. 382; S. C. Webst. P. C. 243, citing Turner v. Winter, Webst. P. C. 77. (h) 2 B. & Ald. 353, Rex v. Wheeler. But it is sufficient if the process be described with as much accuracy as the subject reasonably admits of, and if a criterion, the best according to the knowledge of the inventor, is pointed out. In the patent for the daguerreotype process, in describing the second operation, the specification alleged that the time necessary for the operation could not be stated, because it depended upon several circumstances; but there was a direction that the plate should be kept in the iodine box till it assumed a golden-yellow tint. The Court thought the direction sufficiently plain to be understood by an operator of fair intelligence.(i) 43. Where a general rule is given for the proportions of the ingredients in a composition of matter, it has been held, in the Supreme Court of the United States, that the specification may direct the use of other and variable proportions in exceptional cases, according to the quality of the ingredients employed, though the proportions can only be exactly known after the particular qualities of the ingredients have been ascertained. If the qualities of the ingredients generally differ so widely that the rule given is of no value, or if the improvement cannot be used without ascertaining in every case by experiment the proportions to be employed, the invention is not patentable; if otherwise, the specification is sufficiently certain.(k) 44. The relative proportions of the parts of machinery should be pointed out. In Arkwright's patent, one pair of rollers appeared to be something smaller than the other, but how much, or what were to be the relative dimensions, the specification did not state. (1) There should be a scale or something to enable the workman to form an idea of the relative dimensions of the parts. So it seems that in the specification of a patent for a screw propeller, consisting of sections of a complete screw, the specification should define what section, as whether half or a sixteenth of an entire turn of the screw, is proper to be used.(m) 45. If ingredients are directed to be used in a compo (i) Beard v. Egerton, 8 C. B. 206, 216. (k) Wood v. Underhill, 5 Howard's S. C. R. 1, cited Curtis on Patents, 169. (1) Rex v. Arkwright, Dav. P. C. 108, 112, 122. (m) See Lowe v. Penn, 7 Law Times, 203, Q. B. sition, and the articles which would probably be supplied to a purchaser at a shop in this country, as being those mentioned, are inferior for the purpose of the patent, to others which are only ordinarily procurable abroad, the patentee in the specification should state where they are to be procured of the best description for the purposes of the patent.(n) 46. A patent which casts upon the public the expense and labour of experiments and trial, is undoubtedly bad.(0) Artists of the same trade must be enabled to do the thing for which the patent is granted, without any new inventions or additions of their own. (p) If it be said that the mode of carrying out the process, though not ascertained, will be well and easily known to a person of competent skill, the inventor will not in reality have given any useful information to the public. The specification of a patent for paving-blocks in the form of two solid rhombs, placed one in front of each other in opposite directions, so that each side of one of the blocks was bevelled both outwards and inwards. The angle of the bevel was not stated. Lord Abinger said, unless the jury thought any angle less than a right angle be sufficient, the specification was bad, as experiments would be rendered necessary.(q) 47. The specification ought to be framed so as not to call on a person to have recourse to more than the ordinary means of knowledge (not invention), which a workman of competent skill in his art and trade may be presumed to have. It may upon him to exercise all existing knowledge common to the trade, but nothing more. (r) It need not be so circumstantial or so explanatory, that persons entirely ignorant of the ele-. ments of the science to which the subject belongs, may thereby alone be able to learn and use the invention, nor, on the other hand, should the description be so concise as to become obscure. It must be intelligible and useful to persons of moderate knowledge of the art to which it relates. If a person having call (n) Sturtz v. De la Rue, 5 Russ. 327; Derosne v. Fairie, Webst. P. C. 157. (0) Rex v. Wheeler, 2 B. & Ald. 349, 353. (p) Rex v. Arkwright, Dav. P. C. 106; Webst. P. C. 66. (q) Macnamara v. Hulse, 1 Car. & Mar. 471. (r) Morgan v. Seaward, Webst. P. C. 174, Alderson, B.; Galloway v. Bleadon, Webst. P. C. 524. |