15.The Sampling and Assay of the Precious Metals - by Earnest Smith - Probably the best Classic Text on the subject and still referenced today by Assayers and Chemists. This book covers most ever aspect of precious metals from the Assay Office, Furnaces, Balances, Physical and Chemical Properties of the Precious metals, Sampling, Sample Preparation, Fluxes, Cuppelation and more. It then goes with Chapters specifically on the Assay of Silver, Gold, The Assay of Complex Gold and Silver Ores, The assay of Gold, Silver and Base Bullions, Cyanide Assays, and then the assay of the Platinum Group Metals. 475 Pages Jam packet with information and how to conduct assaying.