Polytechnic Association Proceedings, 923 



GOLD— ITS HISTORY, NATURE, RELATIONSHIP, Etc. 



What a history of joys and sorrows, of expectations and disap- 

 pointments, of virtue and vice, of folly, passion, and crime, could 

 many a small gold dollar, or ducat, relate, were it gifted with 

 intelligence aud speechl What curious hiding-places and scenes 

 could many an old gold coin describe! However interesting and 

 instructive Jis such a history of gold among men would be, it is not 

 the one I propose to bring before you this evening; it is the history 

 of gold in natm-e I contemplate to lay before you. We will trace 

 the precious metal to its rocky hiding-places, and attempt to unravel 

 some of the mystery that seems to enshroud it; we will then give 

 a brief account of its physical and chemical properties, then review 

 its peculiar relationship to other elementary substances, and finally 

 state some of the most effective and successful processes for its 

 extraction from the various ores. 



All modern accounts asfree in tracins; the ori<?in of gold to veins 

 of quartzose and schistose character. Wherever gold is found, 

 either in the sand of rivers, or in diluvial deposits, or in rocks, we 

 ever find it enshrined, or, at least, in close proximity to silica, 

 either as quartz, or as cXixy slate, or as another more complex silice- 

 ous combination. There are some exceptions, however but these 

 are few in number. 



Gold, in varying proportion, is found in most of the metallic 

 sulphurets, arseniurets, and other similar compouuds, either com- 

 bined or free; but these are mostly embedded in quartzose veins, 

 or disseminated in schistose rocks. 



In order to understand more fully why gold is found in the 

 sulphurets and other analogous combinations, and these again are 

 enclosed in quartz veins, we must trace out the origin of quartz itself. 



We have here several pieces of quartz; they all contain various 

 metallic sulphurets, and some show traces of free gold, all of which 

 are firmly embedded in the crystal iue siliceous mass. How did 

 the sulphurets and the gold get into the quartz, and Avhat agency 

 forced the quartz through the fissures of the rocks? 



We all know that quartz is a product of aqueous and not igneous 

 origin. We have ample proofs to that eftect in the presence of 

 volatile metals, such as antimony, arsenic, zinc, and others, also in 

 the presence of water in geodes, and the close proximity to hydrated 

 and carbonated minerals. The theory of the injection of quartz as 

 a glassy, highly-heated mass, by volcanic agency, has been super- 

 seded by the more sensible one of aqueous action. 



