This book, "I. The promoting effect of copper sulfide on the speed of precipitation of zinc sulfide. II. Analytical studies of potassium ferrocyanide. 1", by Elmer Alexander Pearson, is a replication of a book originally published before 1932. It has been restored by human beings, page by page, so that you may enjoy it in a form as close to the original as possible. This book was created using print-on-demand technology. Thank you for supporting classic literature.