DEFENCE-continued. of licensor's want of title, but fraud must be shown, 192. secus in the absence of fraud, 193. to an action for infringement, 292. DESCRIPTION, quality of, required in specification, 109. error in, effect of, 104. distinguished from claim, 117. of applicant's invention in opponent's specification but not DEVOLUTION-continued. by assignment inter vivos, 177. for limited area, 177. See Joint Owners. by way of mortgage, 177. See Assignment; Mortgagee. by grant of licences, 181. See Licence. DIRECTIONS, summons for, in petition for revocation, 271. DIRECTORS of a company, liable for infringement, 217. liability of, for costs, 337. DISCLAIMER. See Amendment of Specification. filed without consent of patertee, struck out by M. R., 155. amendment limited to, when action for infringement or DISCONFORMITY. See Variance. DISCOVERY. See Interrogatories. in aid of inquiry as to damages, 263. DOCTRINE, of mechanical equivalents, 223, 224. of apparent possession in relation to letters patent, 176. DOCUMENTS, sent to Patent Office, size of, &c., 424. amendment of, 426. sent to Patent Office by post, provisions as to, 426. which passed between patentee and patent agent, discovery DRAWINGS, provisions of statute as to, 347. must accompany either provisional or complete specification, size of, 429. optional before 1883...124. omission of, effect, 124. are for purpose of elucidating text, 125. may be read into specification, 125. may not extend scope of claim, 125. amendment of, 158. insertion of, to illustrate amendment, 158. anticipation of invention by, 64. DUPLICATES, of lost patent, when granted, 360. form of application for, 448. of documents required by Comptroller, 425. DURATION of patent, 147. EQUIVALENTS, substitution of known, not subject matter, 45. infringement by, 233 et seq. doctrine of mechanical, meaning of, 223. definition of, 233. ERRORS, in a specification. may or may not vitiate the patent, 104. jurisdiction of M. R. to correct, 155. ESSENCE of an invention, for improved method of attaining old object, 224. ESTOPPEL, of assignor, 188. may not set up defence of invalidity, 188. not prevented from giving evidence in action brought by operation of law, none, 188. of record between Crown and grantee, 188. none against Crown, 188. of assignee, 188. on dissolution of partnership, 189. when partners will be estopped from denying validity of licensee, 189 et seq. judgment obtained by third parties, effect, 194. none, after termination of licence, 190, 193. none, where licensor gave a warranty of validity, 191. none in case of fraud, 192. See Defence. ESTOPPEL-continued. by judgment, 193. does not operate in petition for revocation, 193. EVASION, of patent, 231. See Infringement. EVIDENCE, on opposition to grant, 141, 432. on application by legal representative, 427. on application under international arrangements, 428. on application for compulsory licence, 436. statutory declarations, how made, 426. in support of application for interlocutory injunction, 259. in petition for extension, 458. not received from petitioner, 204. in action for infringement or petition for revocation. commercial success as evidence of invention, 40, 42, 43. for purpose of construction of specification, 96. question that may be put in cross-examination of, of common knowledge, 301. limited to particulars, 290, 301. seal of Patent Office judicially noticed, 144. certificate of Comptroller primâ facie evidence, 385. EXAMINER, appointment of, 382. reference of application and specifications to, 128, 347. jurisdiction of, 153, 154. report of, 128, 129. not published except by order of the Court, 349. does not bind judgment of C. G., 129. EXCLUSIVE LICENSEE. See Licensee. EXECUTION, stay of, 338. EXECUTOR, is the legal representative, 137. may take out patent on behalf of deceased inventor, 10. EXHIBITIONS, provisions of statute relating to exposure of inventions at, 361. rules relating to, 425. EXISTING PATENTS, provisions relating to, 364. EXPERIMENTAL USER, what does not amount to anticipation, 53, 57. by inventor, 57. by one on behalf of inventor, 57. effect of profit resulting from, 57. what does amount to anticipation, 57, 226. See Experiments. EXPERIMENTS. See Experimental User. abandoned as unsatisfactory, effect on subsequent patent, 53. necessary to make earlier description workable, effect on necessary to practise invention satisfactorily, patent may or for manufacturing evidence in view of litigation, looked on EXPERT, may be called in by Law Officer, 142. remuneration of, 142. witness, 321. See Evidence. EXPLANATION. See Amendment of Specification. EXPOSURE, for sale, constitutes prior publication, 52. for sale of book containing description constitutes prior for sale, may not amount to infringement, 243. EXTENSION OF TERM OF PATENT, provisions for, 195, 356. former practice as to, 196. form of petition for, 502. origin of jurisdiction of Privy Council, 196. spirit in which Privy Council approaches subject of, 197. immaterial whether opposed or not, 198. grounds for, must be strictly proved, 198. in spite of consent of Crown, 198. two or more patents of similar nature may be subject of one for a limited area, quære, 210. patents granted prior to 1883, governed by provisions of application for extension of, may be presented any |