A History of Chemistry from Earliest Times to the Present Day pdf epub mobi txt 電子書 下載 在線閱讀 2026

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. Excerpt from book: Section 3CHAPTER II THE AGE OF ALCHEMY In the introduction to this book Egypt is spoken of as the mother-land of Alchemy. The University of Alexandria was especially instrumental in the propagation of the latter during the first centuries of our era; it was the carrier and intermediary for the alchemistic doctrines, more particularly at the time of the fall of the Western Roman Empire. The attempts to convert the base metals into the noble ones had their origin in superficial observations, which appeared to give a strong support to the belief in this transmutation. Among such accidental observations was that of the deposition of copper upon iron utensils left in copper mines from the waters which accumulated there. What more natural than to conclude that a transmutation of iron into copper had occurred ? For the production of gold or silver from copper, the transformation of the latter into yellow or white alloys by means of earthy substances such as calamine or arsenic appeared to give warrant. Finally, the fact that a residue of gold or silver remained behind when an alloy with lead or an amalgam with mercury was strongly heated, indicated the generation of those noble metals. To these considerations of a practical nature, which strengthened the conviction as to the transmutation of metals, but which inferred a gross self-deception on the part of the observer himselfto say nothing of their being turned to good account by crafty knavesthere came to be allied, in this epoch for the first time, the tendency to group together chemical facts from common points of view. It was precisely in the mode in which it was attempted to explain the composition of the metals that there lay a powerful and ever-active charm, leading to the belief in the ennobling of the baser metals and to continually repeated efforts...