112 THE MICROSCOPIST. 



caustic potash or soda a precipitate which, when stirred 

 with a glass rod, becomes a mass of crystals, as in Plate 

 til, Fig. 66. The Sulphocyanide of potassium gives no 

 precipitate. 



Aconitin. No characteristic test, except the physiologi- 

 cal one; yo^th of a grain produces on the end of the 

 tongue a peculiar tingling and numbness, lasting for an 

 hour; T Jo tn grain in alcohol, rubbed on the skin, pro- 

 duces temporary loss of feeling. 



Brucin or Bruda. Potash or ammonia produces stellar 

 crystals. Sulphocyanide of potassium, feathery, or sheaf- 

 like. (Plate III, Fig. 67.) Nitric acid produces a blood- 

 red color, changing to yellow by heat. On cooling the 

 latter and adding protochloride of tin, it becomes a beau- 

 tiful purple. Ferricyanide of potassium, with T ^ O th grain 

 of brucin yields the most brilliant polariscope crystals. 

 (Plate III, Fig. 68). 



Cmchonine. Ammonia produces granular radiating 

 crystals. (Plate III, Fig. 69.) Sulphocyanide of potas- 

 sium six-sided plates, some irregular. (Plate III, Fig. 70.) 



Conine. This alkaloid and nicotin are distinguished 

 from other alkaloids by being liquid at ordinary tempera- 

 tures, and by their peculiar odor. Conine may be known 

 from nicotin by its odor and sparing solubility in water, 

 by yielding crystalline needles to the vapor or solution of 

 hydrochloric acid, a white precipitate with corrosive sub- 

 limate, and a dark-brown precipitate with nitrate of silver. 



Codein. Ammonia or alkalies give a white amorphous 

 deposit. Sulphocyanide of potassium, crystalline needles. 

 A solution of iodine in iodide of potassium, a reddish- 

 brow^ precipitate, which becomes crystalline. This is 

 soluble in alcohol, from which it separates in plates (Plate 

 III, Fig. 71), which appear beautiful in the polariscope. 



Daturin. According to Dr. Wormley, this is identical 

 with atropin. 



Narcotin. In its pure state crystallizes in rhombic 



