Mr. Archer had then been trying it some five or six weeks. His experiments then went on, and in March, 1851, he published it in the Chemist. Let any of your readers procure that Number, and compare Mr. Archer's claim with Le Gray's, who, in 1852, states that he published it in 1850, and gave "the best method that has been discovered up to the present time;" and yet, singularly enough, in his edition of 1851, leaves out this best method entirely.
W. Brown.
Ewell.
Developing Paper Pictures with Pyrogallic Acid, &c.—Have any of your photographic correspondents tried developing their paper negatives with pyrogallic acid? If so, perhaps he would favour the readers of "N. & Q." with the result of his experiments.
In Dr. Diamond's process for paper negatives, he says the paper, after the iodizing solution has been applied, must be dried before soaking in water. I wish to ask whether it may be dried quickly by the fire, or must it be dried spontaneously by suspension, &c.? Again, how long must the paper remain on the sensitive mixture: must it be placed on the sensitive solution, and immediately taken off and blotted, or placed on the sensitive solution, and after some time (what time?) taken off and immediately blotted?
Have any of your readers substituted iodide of ammonium for iodide of potassium, in preparing paper, collodion, &c., and with what success? And have they substituted nitrate of zinc for glacial acetic acid, as recommended in a French work, with any success?
R. J. F.
Replies to Minor Queries.
Waterloo (Vol. vii., p. 82.).—P. C. S. S. conceives that it may be interesting to Philobiblion to learn that the greatest man in the world was not ignorant of the passage in Strada regarding Waterloo, to which Philobiblion refers. From a diary kept for some years, it appears that on Saturday, the 30th of October, 1843, P. C. S. S., who was then on a visit at Walmer Castle, had the pleasure of directing the Duke of Wellington's attention to the passage in question, as translated by Du Ryer (Paris, 1665). He well remembers that the Duke seemed to be greatly struck with it; that he more than once referred to it, in subsequent conversations; and that on the following day he requested P. C. S. S. to furnish him with a transcript, which he doubts not might still be found among the Duke's papers.