After the development of the picture it was washed and fixed in a solution of hyposulphite of soda, 4 ounces to 1 pint of water. The plate was then washed and dried. This is an epitome of the whole of Archer's process for making either negatives or positives on glass, the difference being effected by varying the time of exposure and development. Of course the process was somewhat modified and simplified by experience and commercial enterprise. Later on bromides were added to the collodion, an iron developer employed, and cyanide of potassium as a fixing agent; but the principle remained the same from first to last. When pyrogallic acid was first employed in photography, it was quoted at 21s. per oz., and, if I remember rightly, I paid 3s. for the first _drachm_ that I purchased. On referring to an old price list I find Daguerreotype plates, 2-1/2 by 2 inches, quoted at 12s. per dozen; nitrate of silver, 5s. 6d. per oz.; chloride of gold, 5s. 6d. for 15 grains; hyposulphite of soda at 5s. per lb.; and a half-plate rapid portrait lens by Voightlander, of Vienna, at £60. Those were the days when photography might well be considered expensive, and none but the wealthy could indulge in its pleasures and fascinations. While I lived in Glasgow, competition was tolerably keen, even then, and amongst the best "glass positive men" were Messrs. Bibo, Bowman, J. Urie, and Young and Sun, as the latter styled himself; and in photographic portraiture, plain and coloured, by the collodion process, were Messrs. Macnab and J. Stuart. From the time that I relinquished the Daguerreotype process, in 1857, I devoted my attention to the production of high-class collodion negatives. I never took kindly to _glass positives_, though I had done some as early as 1852. They were never equal in beauty and delicacy to a good Daguerreotype, and their low tone was to me very objectionable. I considered the Ferrotype the best form of collodion positive, and did several of them, but my chief work was plain and coloured prints from collodion negatives, also small portraits on visiting cards. Early in January, 1860, my home and business were destroyed by fire, and I lost all my old and new specimens of Daguerreotypes and photographs, all my Daguerreotype and other apparatus, and nearly everything I possessed. As I was only partially insured, I suffered considerable loss. After settling my affairs I decided on going to America again and trying my luck in New York. Family ties influenced this decision considerably, or I should not have left Glasgow, where I was both prosperous and respected. To obtain an idea of the latest and best aspects of photography, I visited London and Paris.