"The exposure varied from the first plate thirty seconds to a minute and a half, as the light was very poor. No vestige of an outline appeared on removal from the printing-frame. The plates were dipped in water to the surface, and over them was poured a plain solution of pyrogallic acid, four grains to the ounce of water. Soon a faint but clean image was seen, which gradually intensified up to a certain point, then browned all over; hence, the development in the others was stopped at an early stage, the plate washed, and the development continued with fresh pyro, with one drop of a ten-grain solution of nitrate of silver, then re-washed and cleared by a solution of hyposulphite of soda. "The resulting tints were very delicate in detail, of a colour varying between a bistre and olive tint, and after washing dried with a brilliant surface. The colour of the print varied greatly according to the exposure. From the colour and delicacy it struck me that with care to strain the gelatine, or use only the clearest portion, such a process might be utilised for transparencies for the lantern, and the sensitive plates be readily prepared. "Some plates were fumed with ammonia; these fogged under the pyro solution. The proportions set down were only taken at random, and are certainly not as sensitive as might be procured under trials. The remaining emulsion was left shut up in a box in the dark room, and tried on the third day after preparation; but the sensibility had, it seems, greatly diminished, though the emulsion, when rendered fluid by gently warming, appeared creamy, and the bromide thoroughly suspended. Some of this was now applied to some pieces of paper by means of a glass rod, and hung up to surface dry, then dried fully on the warmed level plate, and treated as sensitised paper. "One kind of paper, that evidently was largely adulterated by some earthy base, dried without any brilliancy, but gave, under exposure of a negative for thirty seconds, very nicely toned prints when developed with a weak solution of pyro. Some old albumenized paper of Marion's was tried, the emulsion being poured both on the albumen side, and, in other pieces, on the plain side; but the salting evidently greatly interfered, the resulting prints being dirty-looking and greyed all over. "These papers, fumed with ammonia, turned grey under development. They printed very slowly, even in strong sunlight, and were none of them left long enough to develop into a full print. After washing they were cleared by weak hypo solution. It is very possible the iron developer may be employed for the glass prints, provided the acidification does not render the gelatine soft under a development.