CHEMISTRY AND ITS DEVELOPMENT 213 



suspected by Boyle, Mayow (1669), Boerhaave and others; 

 but it was first actually isolated by Priestley and Scheele 

 in 1774. The nitrogen of the air was isolated by Ruther- 

 ford in 1772. It must be remarked here that the apparatus 

 and manipulations of "pneumatic chemistry" were grad- 

 ually perfected by Boyle, Hales, Moitrel d 'Element, Black 

 and Priestley (the latter having invented the method of 

 collecting gases over mercury), which rendered possible 

 the isolation of gases that are soluble in water. But the 

 precise demonstration of the composition of gases and the 

 introduction of the systematic use of the balance are due 

 to the founder of quantitative chemistry, the French 

 physician and chemist Lavoisier. 



, But before we proceed to further narrate the progress 

 of chemical philosophy, it remains to enumerate briefly the 

 achievements of chemical technology during the reign of 

 phlogiston. In spite of this fundamental error, chemistry 

 was making fairly rapid progress, and this naturally told 

 on the industries. Boyle and Kunkel improved many 

 metallugical processes and the manufacture of glass. The 

 manufacture of iron and steel owed valuable improvements 

 to the researches of Bergman, Gahn, Rinman and Reaumur. 

 Stahl, Scheele, Hellot, Macquer and others introduced new 

 dyestuffs and improved many processes of dyeing. The 

 preparation of zinc was improved by Marggraff and its 

 manufacture on a large scale was commenced at Bristol in 

 1743. The manufacture of sulphuric acid was commenced 

 by Ward at Richmond; and in 1746 lead chambers were 

 first introduced by Roebuck. In 1747 Marggraff dis- 

 covered sugar in beets ; the sugar industry, however, was not 

 born until the beginning of the nineteenth century. Early 

 in the eighteeth century (1703) Bottger was accidentally 

 led to the invention of porcelain, and its manufacture 

 commenced at Meissen in 1710: but the process was kept 

 secret, and the manufacture was confined to Meissen until 

 Reaumur rediscovered it by systematic research, and finally, 

 in 1769, great porcelain works were established at Sevres, 



