Dec. 30. 1854.] 



NOTES AND QUERIES. 



529 



for years devoted himself to science ; and, knowing that 

 Sir H. Davy and Wedgwood had, in 1802, produced the 

 representation of objects on paper by means of sunlight, 

 although they were unable to fix them permanently, had 

 instituted a series of experiments, which resulted in his 

 taking out a patent for what he termed ' calotype,' 

 although it has since been named 'Talbotype,' out of 

 compliment to the inventor. He read a paper on the 

 subject to the Royal Society in 1840 ; and exhibited in 

 1841 portraits taken by his process in Paris, where the 

 system of Daguerre was then making progress. He took 

 out his patent later in that j'ear, and received the Kumford 

 medal for his invention in 1842. Mr. Talbot has since, 

 by means of letters published in The Times, given the 

 benefit of his invention to the public at large, reserving 

 to himself, however, the right of taking portraits for the 

 purpose of sale — a right which he has exercised by 

 granting licences to many persons to use that branch of 

 art. This patent (see ' N. & Q.,' Vol. x., p. 230.) has 

 been followed by three other patents taken out by the 

 plaintiff^ in order to secure certain improvements in the 

 process. The action was brought because the defendant, 

 who is a photographic artist on the collodion system, has, 

 by means of that system, infringed the plaintiff's first 

 patent. 



" Professor Miller, Mr. Brande, Mr. Hofiman, Mr. Med- 

 lock, Mr. Crookes, Mr. Maskelyne, and other scientific 

 gentlemen were examined in support of the plaintiff's 

 case, to show that the collodion process, although in some 

 respects different, is essentially an imitation of the Tal- 

 botype process ; and, even in the most favourable view of 

 the defendant's case, can onty be considered as a farther 

 improvement on the plaintiff's process. They insisted 

 that collodion was used only as a medium in the place of 

 the plaintiff's prepared paper, and had no photographic 

 power per se ; and also that the pyrogallic acid emploj'ed 

 by the defendant was simply more rapid in its process 

 than the gallic acid of the plaintiff. 



" The defendant rested his case on two grounds : first, 

 that the plaintiff's invention was not new, as the process 

 had been discovered and communicated to the public in 

 1839 by the Rev. J. B. Reade ; and next, that the collo- 

 dion process was altogether different from the Talbotype, 

 and therefore no infringement of the patent. The Rev. 

 J. B. Reade, who is now vicar of Stone, near Aylesburj^, 

 was examined ; and gave evidence, that when he lived at 

 Peckham, he had in the course of experiments discovered 

 two processes for obtaining sun pictures. He knew that 

 Sir H. Davy had stated that leather was more sensitive 

 to light than paper; and he therefore, by means of chlo- 

 ride of silver with an infusion of galls, obtained an image 

 which he fixed with hyposulphate of soda. By these 

 means he produced the picture of a magnified flea, and 

 other objects, which he exhibited at a soiree given in 

 1839 by the late Marquis of Northampton to the Royal 

 Society. Mr. Reade, by his second process, used cards 

 glazed with carbonate of lead; he washed these cards 

 with acetic or muriatic acid, and then floated them in 

 iodide of potassium, so as to produce an iodide of lead. 

 He next washed the surface of the card with nitrate of 

 silver, and obtained the image by superposition, while he 

 washed it with an infusion of galls. The effect of the 

 sunlight was immediately to blacken the cards He fixed 

 the image in the same way that he used in the first pro- 

 cess. He was once surprised to find that a figure was 

 brought out after the paper had been momentarily ex- 

 posed to the light, but he had no idea of the mode of 

 developing the invisible image, until he read the account 

 of Mr. Talbot's discoveries. Mr. Reade communicated 

 the results of his experiments in a letter to Mr. Brayley, 

 who read the letter at two lectures given by him in 1839 

 on photography ; but the letter made no mention of the 



use of iodide of potassium in the experiment of the glazed 

 cards. 



" The second ground of defence was, that the collodion 

 process is essentially different from the Talbotype. The 

 collodion process was discovered in 1851 by Mr. Archer, 

 and is as follows : — Take the collodion of commerce, which 

 is gun-cotton and ether; mix it in certain proportions 

 either with iodide of potassium, of ammonia, or of cad- 

 mium ; pour the mixture on a glass, where it forms a film ; 

 immerse the film in a bath of nitrate of silver, and then 

 place it in the camera; when withdrawn, develope it 

 by pyrogallic acid, or protosulphate of iron, or protoni- 

 trate of iron, and finally fix the image with hyposulphate 

 of soda. The image thus obtained is an amphitype ; it 

 appears negative, but becomes positive if anything black 

 is placed on the back of the film, so that it is either nega- 

 tive or positive according to the transmission of light. 

 The negative image likewise produces a positive when 

 transferred to prepared paper. 



" Dr. Normandy, Dr. Stenhouse,Mr. R. Hunt, Mr. Heisch, 

 Mr. T. Taylor, Mr. Thornthwaite, Mr. Eliot, and other 

 scientific persons gave evidence that collodion possessed 

 unknown photographic properties, and that pyrogallic 

 acid was more highly sensitive and rapid in its action, 

 and was in many respects different from gallic acid ; in- 

 deed, some of the witnesses gave their opinion that pyro- 

 gallic acid was a misnomer, and that the substance was 

 no acid at all. As a proof of the instantaneous action of 

 the collodion process, portraits of animals taken when in 

 the act of motion were shown in court, and also beautiful 

 views of Elsinore, and the Three Crown Batter}' at Copen- 

 hagen, taken on board of Her Majesty's ship Calliojje 

 when passing those places at the rate of eleven knots an 

 hour. The plaintiff likewise produced many views taken 

 by the Talbotype process, and one, not excelled by any in 

 court, of Laycock Abbe}', taken in the year 1842. 



"The Chief Justice summed up with remarkable clear- 

 ness and precision. He pointed out that the plaintiff had 

 made discoveries in the photographic art, had communi 

 cated those discoveries to the Royal Society, and had 

 therefore given the benefit of them to the world, but he 

 had afterwards taken out a patent for new and fresh in- 

 ventions, which he described in his specification. In the 

 first part, however, of that document, he described the 

 method of making iodized paper, but did not claim it as 

 part of the invention. The specification then showed how 

 to make that iodized paper more sensitive by washing it 

 in gallo-nitrate of silver, which was made by a mixture of 

 nitrate of silver and acetic acid with gallic acid. He 

 claimed, then, first, the employment of gallo-nitrate of sil- 

 ver on iodized paper; secondly, the use of gallo-nitrate of 

 silver, or an equivalent, for the purpose of developing and 

 strengthening the photographic image ; and, thirdly, the 

 obtaining portraits from the life by the previously de- 

 scribed means. The fourth claim was not in dispute be- 

 tween the parties. His Lordship stated that the first 

 question for the jury was, whether Mr. Reade had pre- 

 viously discovered and published any material part of the 

 claims set up in the patent. Mr. Reade's first process 

 employed chloride of silver, and not nitrate of silver, and 

 was therefore different from the plaintiff's discover)'. His 

 other process, however, with the glazed cards was, in 

 reality, identically the same with the plaintiflTs, as regarded 

 the method of preparation for giving sensitiveness ; gallo- 

 nitrate of silver was employed in both. But Mr. Reade 

 had not mentioned in his letter the use of iodide of potas- 

 sium, so that in that respect, whether he had used it or 

 not, his description of the method was different from that 

 employed by the plaintiff, who used iodized paper. The 

 letter therefore onh' proved that Mr. Reade was aware of 

 the combination erf nitrate of silver with gallic acid as a 

 sensitive agent, and the publication of the letter by Mr. 



