Frederick Scott Archer pursued the double occupation of sculptor and photographer at 105, Great Russell Street. It was there he so persistently persevered in his photographic experiments, and there he died in May, 1857, and was interred in Kensal Green Cemetery. A reference to the report of the Committee will show what was done for his bereaved family--a widow and three children. Mrs. Archer followed her husband in March, 1858, and two of the children died early; but one, Alice (unmarried), is still alive and in receipt of the Crown pension of fifty pounds per annum. While the collodion episode in the history of photography is before my readers, and especially as the process is rapidly becoming extinct, I think this will be a suitable place to insert Archer's instructions for making a _soluble_ gun-cotton, iodizing collodion, developing, and fixing the photographic image. _Gun-Cotton_ (_or Pyroxaline, as it was afterwards named_). Take of dry nitre in powder 40 parts Sulphuric acid 60 " Cotton 2 " The sulphuric acid and the nitre were mixed together, and immediately the latter was all dissolved, the gun-cotton was added and well stirred with a glass rod for about two minutes; then the cotton was plunged into a large bowl of water and well washed with repeated changes of water until the acid and nitre were washed away. The cotton was then pressed and dried, and converted into collodion by dissolving 30 grains of gun-cotton in 18 fluid ounces of ether and 2 ounces of alcohol--putting the cotton into the ether first, and then adding the alcohol; the collodion allowed to settle and decanted prior to iodizing. The latter operation was performed by adding a sufficient quantity of iodide of silver to each ounce of the plain collodion. Mr. Archer tells how to make the iodide of silver, but the quantity is regulated by the quantity of alcohol in the collodion. When the iodized collodion was ready for use, a glass plate was cleaned and coated with it, and then sensitised by immersion in a bath of nitrate of silver solution--30 grains of nitrate of silver to each ounce of distilled water. From three to five minutes' immersion in the silver bath was generally sufficient to sensitise the plate. This, of course, had to be done in what is commonly called a _dark room_. After exposure in the camera, the picture was developed by pouring over the surface of the plate a solution of pyrogallic acid of the following proportions:-- Pyrogallic acid 5 grains Distilled water 10 ounces Glacial acetic acid 40 minims