Wilsons Photographic Magazine Volume 49 PDF Download

Excerpt from Wilson's Photographic Magazine, Vol. 40 At this period all waste solutions were thrown away in the course of manipulation. The few photographers interested in the saving and refining of silver and gold from printing-room wastes turned their attention to the saving of platinum waste, but even this was gradually abandoned, owing to the fact that platinum printing was not general as it is to-day. The process then employed consisted of collecting the various develop ing solutions, boiling them down in a large evaporating pan (of Berlin porcelain) and adding hydrochloric acid and chloride of ammonium, so as to form a yellow powder, known as ammonium-chloro-platinate. This, upon being heated to a white heat in a crucible, produced a residue of platinum black, or spongy platinum. The directions issued by the manufacturers of the paper usually informed the photographer that the acid-clearing solutions used after develop ing might be thrown away, as they were not worth saving. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.