ALKALOIDS. 327 



solves the alkaloids. The filtered alcoholic solution is slightly 

 acidulated with sulphuric acid, and then evaporated to expel the 

 alcohol. The residue is mixed with a little water, and the clear 

 solution, containing the alkaloids as sulphates, is precipitated 

 by sodium hydrate. The precipitated alkaloids are collected on 

 a small filter, washed and dried at 100. 



From the total alkaloids the quinine is separated by dissolving 

 them in water acidulated with sulphuric acid, and adding to 

 this solution (which should be just distinctly acid to test-paper, 

 and should weigh seventy times as much as the alkaloids used) 

 diluted solution of sodium hydrate until exactly neutral, when 

 the "effloresced sulphate of quinine," (C 20 H 24 ^" 2 2 ) 2 .H 2 SO 4 .2H 2 0, 

 separates; this is collected on a small filter, dried at 60, and 

 weighed. 



The precipitation of the salt is facilitated by heating the 

 mixture to about 60 for five minutes, and subsequent cooling 

 to 15 for half an hour. 



As sulphate of quinine is soluble in water of 15 to the ex- 

 tent of 0.12 per cent., the filtered liquid has to be weighed, and 

 for every 100 grams of the filtrate 0.12 gram has to be added 

 to the weight of the quinine sulphate collected on the filter. If 

 the quantity of quinine in the alkaloids be too small, or the 

 quantity of the filtered liquid too large, no separation of the 

 salt may take place. In order to calculate from the precipitated 

 "effloresced sulphate of quinine" the quantity of "crystallized 

 sulphate of quinine," 11.5 per cent, of its weight have to be 

 added for water of crystallization. 



Quinine, Quinina, C 20 H 24 N 2 2 .3H 2 = 378. This formula repre- 

 sents the crystallized alkaloid, but it is also known as anhydrous, 

 and in combination with either one or two molecules of water. 

 The anhydrous quinine is a resinous substance, whilst the crys- 

 tallized quinine is a white powder, having a bitter taste and an 

 alkaline reaction. It is nearly insoluble in water, but soluble 

 in alcohol, ether, and chloroform. 



Quinine sulphate, Quininae sulphas, (C 20 H 24 N 2 2 ) 2 H 2 S0 4 .7H 2 = 872 



(Sulphate of quinine). This salt, containing two molecules of the 

 alkaloid in combination with one of sulphuric acid arid seven 

 of water, is the common form of sulphate of quinine. It forms 



