July 8. 1854.] 



NOTES AND QUERIES. 



35 



of Saint Andrew's, in Scotland, now residing at No. 44. 

 Saint James's Place, Westminster, Knight, make oath, and 

 say as follows : 



1. I have for many years paid much attention to op- 

 tical science, and 1 have written treatises on that science 

 generally, and on different branches of it. 



2. I have paid much attention to the art of Photo- 

 graphy, and have written and published various writings 

 concerning the history and progress of that art. 



3. I have been acquainted with the piiotographic 

 process invented by the plaintiff, and at first called by 

 him the calotype process, and described in the specification 

 marked X., shown to me at the time of my making this 

 affidavit, from the time, or nearly so, of the first publi- 

 cation of it by him, videlicet, from the year 1841, and I 

 fully believe that he was the first and true inventor of the 

 said calotype process, and I say that such is the general 

 opinion of scientific men, according to the best of my 

 knowledge and belief. 



4. That I was the first, or one of the first, persons who 

 proposed and maintained that the name of Calotype ought 

 to be changed to that of Talbotype, after the name of the 

 inventor. 



5. That I am acquainted with the principle of what 

 has been termed the collodion process in photography, 

 and that I consider it to be a useful and convenient mode 

 of operating. 



6. That by employing the said collodion process a 

 greater rapidity of photographic action is frequently ob- 

 tained, together with a greater precision and clearness in 

 the negative image or picture. 



7. That the said collodion process consists chiefly in a 

 mode of obtaining the negative pictures upon a film or 

 skin of iodized collodion spread upon glass, instead of ob- 

 taining them upon a sheet of iodized paper according to 

 the plaintitFs invention, described in the said specification. 



8. That I consider the said collodion process to be only 

 a variation or modification of the plaintiff's said in- 

 vention, called by him the calotype, for the following 

 reasons, videlicet : — 



First. — Because the skin of iodized collodion spread 

 upon glass serves as a substitute for the sheet of 

 iodized paper employed by the plaintiff. 



Secondly. — Because, in both cases, the iodized sur- 

 face (whether collodion or paper) requires to be 

 excited or rendered sensitive to light by washing 

 it over with a solution of nitrate of silver, or by 

 dipping it in a bath of the same. 



Thirdly. — Because, in both cases, after an invisible 

 image has been impressed upon the photographic 

 surface (whether of collodion or paper), it is re- 

 quisite to develop it or render it visible by washing 

 it with a liquid (which is the chief and principal 

 part of the plaintiff's said invention): and the 

 liquid generally employed for that purpose is either 

 gallic acid as described by the plaintiff in his said 

 specification, or a modification of the same, termed 

 pyrogallic acid. 



Fourthly. — Because (whether the first or negative 

 image is obtained upon collodion or upon paper), 

 in either case, the final result of tlie process is the 

 same, videlicet, a positive picture is obtained upon 

 paper by the action of light. 



9. That I have read a copy of the joint and several 

 affidavits purporting to be made by liobert Hunt and 

 Charles Heisch, sworn in this cause on the 22nd day of 

 this present month of May; also copies of two several 

 affidavits purporting to be made by Alphonse Normandy 

 and William Henry Thornthwaite, both sworn in this 

 cause on the same 22nd day of May instant ; and that, 



notwithstanding such affidavits, I fully believe that the 

 plaintiff was the first and true inventor of the calotype 

 process described in his said specification, and that the 

 said calotype process was very different from any photo- 

 graphic process previously known ; and I say that the 

 distinction attempted to be drawn in the said aflidavits 

 between the collodion and calotype processes is fallacious, 

 inasmuch as the collodion process borrows from the calo- 

 type process its most essential point, videlicet, the develop- 

 ment of an invisible image, and therefore it ought to be 

 considered merely as an improvement upon the latter 

 process. 



David Bkeavstek. 



Sworn at my chambers, No. 6. New Square, Lin- 

 coln's Inn, in the county of Middlesex, this 

 24th day of May, 1854, before me, 



W. Strickland Cookson, 

 A London Commissioner to administer 

 oaths in Chancery. 



In Chancery. — Between William Henpy Fox 

 Talbot, Plaintiff, and James Henderson, De- 

 fendant. 

 I, John Frederick William Herschel, Baronet, 

 Master of Her Majesty's Mint, make oath, and say as 

 follows : 



1. I have read a copy of an affidavit sworn in this 

 cause by Robert Hunt and Charles Heisch on the 22nd, 

 and filed on the 23rd of May instant, in which my name 

 is mentioned in the following terms, videlicet : 



" Sir John Herschel also published the fact of his having 

 used gallic acid in a paper communicated by him to the 

 Royal Society on February 20th, 1840, and which paper 

 is printed and published in the Philosophical Transac- 

 tions." 



2. I say that the inference attempted to be drawn to 

 the prejudice of the plaintiff from my memoir in the 

 Philosophical Transactions, above referred to, is erroneous ; 

 inasmuch as in the experiments there referred to, I did 

 not use gallic acid for the purpose of developing a dorma,nt 

 picture, not being then aware that any such dormant pic- 

 ture existed, but only with a view to increase the sensi- 

 tiveness of the paper. 



3. I say that my memoir, above referred to, extended 

 to nearly sixty pages, and that gallic acid is only once 

 named in it, to the best of my recollection, videlicet, at 

 page 8, in the following words : 



" My first attention was directed to the discovery of a 

 liquid or emulsion, which, by a single application, whe- 

 ther by dipping or brushing over, should communicate 

 the desired quality. The presence of organic matter 

 having been considered by some late chemists an essen- 

 tial condition for the blackening of the nitrate of silver, I 

 was induced to try, in the first instance, a variety of mix- 

 tures of such organic, soluble, compounds as would not 

 precipitate that salt. Failing of any marked success in 

 this line (with the somewhat problematic exception of 

 the gallic acid and its compounds), the next idea which 

 occurred, was ..." 



4. I say, that in writing the passage of my memoir 

 above quoted, I did not contemplate the photographic 

 process, since called the calotype process ; nor was I then 

 acquainted with that process. 



6. I say that I have been acquainted with the plaintiff's 

 invention, called the calotype process, from the time, or 

 nearly so, of its first publication in 1841 ; and that I con- 

 sider the leading feature in the plaintiff's said invention 

 to have been the discovery of the existence of invisible 

 photographic images on paper, and the mode of making 

 them visible, described by the plaintiff. And I say that 



