THE GENEALOGY OF CHEMISTRY. 537 



form. The long history of its successive advances and its systematic 

 tentatives, in both the practical and the philosophical departments, is 

 most remarkable. 



In the period that followed the Alexandrine epoch and pre- 

 ceded the definite recognition and naturalization of alchemy in 

 western Europe, in the thirteenth century, the name of the Arabians 

 is predominant; and the most widely known authors usually ascribe 

 to them the progress which the Greeks made in most of the sci- 

 ences. They have sometimes even gone so far as to attribute to 

 the Arabs the discovery of chemistry — a view which has to be 

 abandoned on obtaining an exact knowledge of the original authors. 



I have devoted nearly ten years to the study of this subject, 

 and have published for the first time the texts of the Grecian chem- 

 ists, as well as those of their Syrian and Arabian followers, drawing 

 them from their hiding places in the libraries of London, Paris, and 

 Leyden — works which no one would read, because they were sup- 

 posed to be chimerical and unintelligible. Yet there is a real and pro- 

 found science in these old texts, mingled, it is true, with erroneous 

 notions concerning the transmutation of metals, and with illusionary 

 and often charlatanish pretensions. 



Except gold, which has been mined native from the earliest times, 

 pure metals are rarely found in ISTature. A native alloy of gold and 

 silver is found in similar conditions as gold, which was called white 

 gold or electrum by the ancients, and was considered a separate 

 metal till the sixth century a. d. It was used as a material for 

 money by the Lydians, and by the Grecian cities of Asia Minor, till 

 near the time of Alexander. This alloy, however, has no constant 

 properties, for the relative proportions of its two components are 

 variable. By reason of this diversity it had an important place in 

 the thought and attempts of the alchemists seeking for the trans- 

 mutation of metals; for we can extract gold or silver from it at 

 will, according to the treatment we give it. Hence the opinion that 

 electrum was susceptible of being changed into one or the other of 

 these two noble metals. 



These notions and experiments were confirmed by the metallur- 

 gical methods employed in the fabrication of other metals. Iron, 

 copper, lead, tin, and silver do not exist as such in ISTature except 

 in unusual minerals. They are ordinarily found in oxide or sul- 

 phide compounds, and are, when separate, products formed by 

 human art. In fact, it is by submitting these compounds to more 

 or less complicated reactions, in which fire, combustible agents, 

 drying, or roasting in contact with the air are applied, that the dif- 

 ferent metals are prepared. These preparations were formerly made 

 according to a traditional empiricism, the origin of which is lost in the 



