179 



Oxamide. 

 I'alinine. 

 Pnlmic acid. 

 Aniygdaline. 

 Tannin, pure. 

 Quinine, pure. 



acetate of. 



sulphate of. 



muriate of. 

 ... . phosphate of. 



citrate of. 

 Cacao butter. 

 Veratric acid. 

 Esculine. 

 Theine. 



Silver, cyanide of. 

 acetate of. 

 Platinum & magnesium, cyanide of. 



and barium, cyanide of. 



and potassiuu,cyanide of . 



ammonia, chloride of. 

 Potash, chlorate of. 



chromate of. 

 Urea, nitrate of. 

 Sulphur. 

 Camphor. 

 Cinchonine. 



Cinchonine, sulphate of. 

 Meconic acid. 

 Brucine, sulphate of. 

 Morphia, acetate of. 

 Tin, iodide of. 

 Cerium, oxide of. 

 Parmeline. 

 Lecanorine. 

 Indigo, red. 

 Ammonia, oxalate of. 

 sulphate of. 

 Soda, chromate of. 

 Lead, iodide of. 

 Strychnine, sulphate of. 



acetate of. 

 Soda, nitrate of, native. 

 Berberine. 

 Mucic acid. 

 Solanine. 

 Asparagine. 

 Mercury, bichloride of. 

 Isatine. 

 Alizarine. 



Manganese, sesquioxide of. 

 Lead, protoxide of. 

 Tungstic acid. 

 Oxalate of chromium and potash. 



In many substances, when subjected to pressure and traction, the 

 particles exhibit no such arrangement into transparent streaks, as 

 in the above, but are merely dragged into lines, and exhibit a qua- 

 quaversus polarization. But there is another class, which yields 

 transparent streaks, without any trace of prismatic arrangement. 

 Such are the bodies in the following list : — 



Hydrate of potash, pure. 



Indigotic acid. 



Urea. 



Citric acid. 



Silver, nitrate of. 



Meconine. 



Napthalinc. 



Soda, nitrate of, pure. 



Potash and copper, sulphate of. 



Soda, phosphate of. 



Soda, acetate of. 

 Mercury, cyanide of. 



chloride of. 



sulphuret of. 

 Baryta, acetate of. 

 Zinc, chromate of. 

 ... sulphate, of. 

 Cobalt, sulphate of. 

 Magnesia and soda, sulphate of. 

 Borax. 



Compression is, no doubt, the agent which forces the particles into 

 optical contact, and traction draws them into a line, tending to sepa- 

 VOL. III. p 



