

Experiment. 







Calculation. 





I. 



ii. 



in. 









70-71 



70-60 



70-58 



70-79 



C40 



240 



6-29 



6-46 



6-46 



6-20 



C 21 



21 



4-40 



3-96 



• • • 



4-14 



N 



14 



18-60 



18-96 



... 



18-78 



o 8 



64 



198 DR t. ANDERSON ON SOME OF THE 



Carbon, 

 Hydrogen, 



Nitrogen,* 

 Oxygen, 



100-00 100-00 100-00 339 



These results correspond completely with the calculated numbers, and were 

 sufficient to show that the base is papaverine, but for further security, a determi- 

 nation of the platinum in its platinum salt was made, with the following results : — 



( 5-684 grains of platinum salt gave 



\ 1-013 ... platinum = 17'82 per cent. 



This corresponds with calculated result, which gives 18-10 per cent. 



The salts of papaverine having been already sufficiently investigated by Merck, 

 I did not think it necessary to extend my experiments in this direction, but pro- 

 ceeded to examine the action of various agents upon the base itself. 



Action of Nitric Acid. 



Papaverine dissolves in dilute nitric acid without decomposition, and with the 

 formation of a nitrate ; but if the solution be mixed with an excess of nitric acid, 

 especially if concentrated, and heat be applied, a brisk action takes place, some 

 red fumes are evolved, the fluid becomes dark red, and orange-coloured crystals 

 begin to make their appearance, and gradually increase in quantity. Nothing 

 can be simpler than the preparation of this substance. The degree of concentra- 

 tion of the acid is immaterial, for the product is sure to be obtained ; and if the 

 fluid be sufficiently concentrated, crystals begin to be formed the instant the heat 

 is applied, and soon become so abundant as entirely to fill the fluid. If the solu- 

 tion be more dilute, they appear more slowty, and are then larger, more regu- 

 larly formed, and much paler coloured. The only precaution necessary is, to 

 avoid the use of too large an excess of nitric acid, as it dissolves the new product 

 much more abundantly than water. The orange- coloured crystals are the nitrate 

 of a new base, to which I give the name of nitropapaverine. 



Nitropapaverine — is readily obtained from its nitrate, by dissolving it in 

 boiling water, and precipitating the hot solution by ammonia ; but as the salt is 

 very sparingly soluble, even in hot water, it is more convenient to dissolve it in 

 nitric acid, and then to add at once an excess of the alkali. A light yellow floc- 

 culent precipitate is immediately deposited, which is collected on a filter, dried, 



* Merck lias published only one nitrogen determination of papaverine, giving 4 - 75 per cent., 

 which greatly exceeds the calculated number. I have observed the same tendency to give an excess, 

 having in one experiment obtained as much as 4-66. The only mode of explaining this anomaly, 

 was by supposing that the base carried down a small quantity of the ammonia which had been used 

 to precipitate it. In order to ascertain whether this opinion was well-founded, a quantity thrown 

 down by potash was analysed, and the results are those of the second determination. 



