CRYSTALLINE CONSTITUENTS OF OPIUM. 199 



and dissolved in boiling alcohol, from which it is deposited on cooling. Nitro- 

 papaverine is thus obtained in pale buff-coloured needles, insoluble in water, but 

 soluble in alcohol and ether. It restores the blue colour of reddened litmus, dis- 

 solves in the acids, neutralizes them completely, and forms a series of salts, all of 

 which have a pale buff colour and are sparingly soluble in water. When heated, 

 it undergoes fusion, and at a higher temperature it burns rapidly with a sort of 

 deflagration. Concentrated solution of potash, when boiled with it, causes the 

 evolution of traces of a volatile base. It does not give the purple reaction of pa- 

 paverine with sulphuric acid. Its analysis gave the following results : — 



{5-065 grains of nitropapaverine, dried at 212°, gave 

 11-573 ... carbonic acid, and 

 2-640 — water. 



Experiment. Calculation. 



Carbon, . . . 62-31 62-50 C 4U 240 



Hydrogen, . . 5-21 5-20 H 20 20 



Nitrogen, . . ... 7'29 N 2 28 



Oxygen, ... ... 25-01 12 96 



100-00 384 



This corresponds closely with the calculated results for the formula 



C 40 H 20 (NO,) 8 

 which is further confirmed by the analysis of the platinum salt given below. 



The crystals of the base deposited from alcohol are a hydrate, as indicated by 

 the subjoined experiment. 



{5 - 237 grains of nitro-papaverine dried in the air, 

 lost at 212° 0-14 grains = 2-67 per cent. 



One equivalent of water requires 229 per cent., so that the crystals have the for- 

 mula C 40 H 20 (NOj 3 + HO. 



Nitrate of Nitropapaverine. — This salt is obtained by the action of nitric acid 

 on papaverine, in the manner already described. It appears in the form of four- 

 sided tables, sometimes of considerable size, and generally of a dark orange colour. 

 By crystallization from boiling alcohol, it is got in a state of absolute purity, and 

 then forms fine yellow crystals of great beauty. It is almost insoluble in cold 

 water, but on boiling it is taken up in somewhat larger quantity, and deposited 

 on cooling in an imperfectly crystalline form. It is much more soluble in water 

 containing nitric or hydrochloric acids, as well as in alcohol and ether. When 

 gently heated it melts, and then deflagrates, leaving a quantity of a nearly black 

 substance, which burns away completely at a higher temperature. Potash and 

 ammonia, when digested on it at ordinary temperatures, rapidly separate the base. 

 The ease with which this substance is formed, and its extreme insolubility render 

 its production a very useful reaction for papaverine, and by means of it I have 

 succeeded in proving that this base also occurred in the fluid from which narco- 



VOL. XXI. PART I. 3 H 



