CRYSTALLINE CONSTITUENTS OF OPIUM. 



203 



Experiment. 





Calculation. 





33-02 



33-47 



^40 



240 



3-21 



2-92 



H 2l 



21 



. 



1-95 



N 



14 





8-95 



8 



64 



52-90 



52-71 



I 3 



378 





100-00 



717 



3 therefore 









C 40 H 21 NO s + I 3 . 









Carbon, . 



Hydrogen, 



Nitrogen, 



Oxygen, 



Iodine, 



The formula of the substance is therefore 



Pentiodide of Papaverine. — By evaporating the mother liquor of the teriodide 

 this compound is deposited, and is purified from excess of iodine by crystalliza- 

 tion from alcohol. It then forms slender needles, with an orange colour by trans- 

 mitted light, and a reddish-bronze surface colour. It is much more soluble in 

 alcohol than the teriodide, but is insoluble in water. It loses iodine by the ap- 

 plication of a moderate heat, although perfectly stable at 212°. It is insoluble in 

 acids, and is rapidly decomposed by ammonia. Its composition was : — 



{5-502 grains pentiodide of papaverine gave 

 5*000 ... carbonic acid, and 

 1-283 ... water. 



( 3902 grains pentiodide gave 

 14-665 ... iodide of silver. 





Experiment. 



24-78 



Calculation. 





Carbon, 



24-76 C 40 



240 



Hydrogen, . 



2-59 



216 H 21 



21 



Nitrogen, 



. 



1-44 N 



14 



Oxygen, 



. 



6-63 8 



64 



Iodine, 



64-60 



65-01 I, 



5 



630 



100-00 



969 



These results give the formula 



C 40 H 21 N0 8 + I 5 . 



It is difficult to form a rational conception of the constitution of these sub- 

 stances. The formulae given above seem to be on the whole the most probable ; 

 but it is clear that the analyses admit of a different interpretation, and we may 

 assume these compounds to be hydriodates with excess of iodine, and represent 

 their constitution by the formulae 



C 40 H 21 N0 8 HI + I 2 

 C 40 H 21 N0 8 HI + I 4 



the additional atom of hydrogen making too small a difference to be important. 

 We have, however, no experiments to enable us to decide between these two 

 views, which could only be done by an extended investigation of the similar com- 

 pounds of the other bases ; and in the absence of further information, I have 

 VOL. xxi. part i. 3 I 



