J. Leachman.
20. Compton Terrace, Islington.
Dr. Diamond's Process for Albumenized Paper.—Photographers are under many obligations to Dr. Diamond, particularly for the valuable information communicated through "N. & Q.," and his obligingness in answering inquiries. I make no doubt he will readily reply to the following questions, suggested by his late letter on the process for printing on albumenized paper.
Will the solution of forty grains of common salt and forty grains of mur. amm., without the albumen, be found to answer for ordinary positive paper (say Canson's, Turner's, or Whatman's)? and, in that case, may it be applied with a brush?
Will the forty-grain solution of nit. sil. (without amm.) answer for paper so prepared? and may this also be applied with a brush?
Should the positives be printed out very strongly? and how long should they remain in the saturated bath of hypo.?
Is not the use of sel d'or subject to the objection that the pictures with which it is used are liable to fade in time?
Dr. Diamond says that pictures produced by the use of amm. nit. of silver are not to be depended on for permanency. If this be so, it is very important it should be known, as the use of amm. nit. is at present generally recommended and adopted.
C. E. F.
Mr. Lyte's New Process.—Although I presume it is none of your affair what is said or done in "another place," will you kindly ask Mr. Lyte for me, if he will be so good as to explain the discrepancy which appears between his "new processes," as given in the Journal of the Photographic Society of Sept. 21, and "N. & Q." of Sept. 10? In the former he says, for sensitizing, take (amongst other things) iodide of ammonia 60 grains: in "N. & Q.," on the contrary, what would seem to be the same receipt, or intended as the same, gives the quantity of this salt one fourth less, 45 grains—a vast difference. Again, in the developing solution the quantity of formic acid is double in your paper what it is in the journal.