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A TEXT-BOOK OF BOTANY. 



tion method, that they contained arbutin. The latter is a rather 

 widely distributed glucoside in this family and yields upon treat- 

 ment with solutions of emulsin or hydrochloric acid the sublimable 

 principle hydrochinon. The latter forms prisms and plates and 

 may be further examined with acetone solution, dilute solutions of 



FlG. 10 1. Alkaloids of hydrastis obtained by microsublimation. The method fol- 

 lowed by Tunmann is to mix from o.oio to 0.050 Gm. of powdered hydrastis with a drop of 

 water upon a glass slide and heat to a temperature of 80 to 95 C. The sublimate consists 

 of a number of radiating particles in which different types of crystals very soon separate (A). 

 The microsublimate may be further treated with alcohol and a solution of potassium iodide, 

 when crystals of hydrastine (B) and needle-shaped crystals of berberine (C) form. After 

 Tunmann in Gehe & Co.'s Handelsbericht, 1912. 



ferric chloride and ammonia water. Arbutin occurs in the 

 leaves of Arctostaphylos Uva-ursi, Vaccinlum Myrtillus, Kalmia 

 angustifolia, and Pyrola rotundifolia. 



Rosenthaler obtained definite crystals in the microsublimation 

 or pyro-analysis of the following drugs : cinchona, uva-ursi, f ran- 



