I RAW MATERIALS AND PRIMITIVE MANUFACTURES 11 



(2) An Earlier Alchemistic Period, extending to about 

 1500 A.D., during which many substances were discovered in 

 the attempt to convert base metals into gold ; 



(3) A Later Alchemistic Period, extending to about 1650 A.D., 

 in which new substances were prepared and tested for 

 medicinal purposes. 



Important substances known at a very early date include : 



1. Soluble Salts. 



Common Salt (Sodium chloride, NaCl). 

 Washing Soda (Sodium carbonate, Na 2 CO 3 ,ioH 2 O). 

 Potash (Potassium carbonate, K 2 CO 3 ). 

 Saltpetre or Nitre (Potassium nitrate, KNO 3 ). 

 Sal-ammoniac (Ammonium chloride, NH 4 C1). 



2. Earths and Rocks. 



Fuller's Earth. 



Chalk, Limestone, Marble (Calcium carbonate, CaCO 3 ). 



Sand, Quartz (Silicon dioxide, SiO 3 ). 



Emerald. Topaz. Diamond. 



3. Organic Products. 



Sugar. Turpentine. Oils, Fats and Waxes. Amber 

 and Pearls. Wine and Vinegar. Saltpetre and 

 Sal-ammoniac. 



4. Igneous Products. 



Lime from Limestone (CaCO 3 -> CaO + CO 2 ). 

 Tin (stannum, Sn) from Tinstone 



Iron (ferrum, Fe) from Ironstone 



Litharge from Lead (2Pb + O 2 -> 2PbO). 



Also Native Metals. 

 Gold (aurum, Au). 

 Silver (argentum, Ag). 

 Copper (cuprum, Cu). 

 Mercury (hydrargyrum, Hg). 



5. Products of Decay. Especially, Iron Pyrites (FeS 2 ) 

 -> Green Vitriol (Ferrous sulphate, FeSO 4 ,7H 2 O) 

 -> Oil of Vitriol (Sulphuric acid, H,SO 4 ). . 



