CHEMISTRY AND ITS DEVELOPMENT 205 



to assert that "a vessel will hold as much water when 

 filled with ashes as when empty"? 



However, the ancients knew some facts which lie within 

 the scope of modern chemistry. Most of that knowledge 

 was gained empirically by the Egyptians, and was by them 

 communicated to the Jews and Phoenicians, and later to 

 the Greeks and Romans. The metallurgy of gold, silver, 

 copper, iron, lead, tin, mercury, and perhaps zinc, and the 

 preparation of certain alloys, were known at quite an early 

 date. The Egyptians had highly developed the art of 

 making glass and of coloring it by means of certain 

 metallic oxides, and many extant - specimens of Egyptian 

 pottery are beautifully enameled in various colors. The 

 art of dyeing fabrics by the aid of mordants had likewise 

 been developed at an early date, and many mineral and 

 organic coloring matters were known to the Egyptians, 

 Phoenicians and Jews. The Egyptians were also probably 

 the first to compound substances for medicinal purposes. 



The arts of metallurgy and of dyeing remained through 

 the Middle Ages practically what they had been in Egypt 

 long before the beginning of our era. Nevertheless, the 

 alchemists, in their search after the philosopher's stone, 

 discovered methods of preparing many new substances, 

 perfected many processes of manipulation, and thus slowly 

 paved the way for future investigators. Bismuth and 

 antimony, sulphuric, hydrochloric and nitric acids, the 

 chloride and carbonate of ammonium, the nitrates of 

 potassium and silver, compounds of mercury, antimony 

 and arsenic these and many other important substances 

 were first prepared and their properties were first studied 

 by the alchemists. Of course the interpretation of the 

 known facts was absurd, based as it often was upon the 

 most groundless assumptions for instance, the assumption 

 that most substances, and all metals contained sulphur. As 

 to the compounds of carbon, the alchemists did hardly any- 

 thing toward laying a foundation for future organic 

 chemistry, although they learned to concentrate aqueous 



