DESTRUCTIVE DISTILLATION OF ANIMAL SUBSTANCES. 215 



I. II. III. IV. V. 



Carbon, 



. 75-51 



75-36 



7618 



74-23 



77-47 



Hydrogen, . 



846 



871 



813 



858 



8-47 



Nitrogen, 



. 1603 



1593 



15-69 



171 9 



1406 



10000 10000 100-00 10000 10000 



It must be distinctly understood that all the substances analysed were 

 obviously mixtures, and the degrees above given do not denote true boiling 

 points, but only that the fractions they represent were collected at these points. 

 It will be observed that all these analyses are characterised by yielding a per- 

 centage of hydrogen far above that contained in pyridine, or any of its homo- 

 logues. To render this more obvious, I place here the calculated numbers for 

 pyridine and picoline, along with those required by bases containing two atoms 

 of hydrogen more than these compounds : — 



C.H.N C^N C 5 H 7 N C e H,N 



Carbon, . . 7594 7742 7404 7575 



Hydrogen, . . 6-33 7"53 8-64 9-47 



Nitrogen, . . 17*73 15-05 17-32 14-78 



10000 10000 100-00 100-00 



The experimental results above given are manifestly incompatible with the first 

 two of these formula, but would agree tolerably with a mixture of substances 

 containing more hydrogen, and this is further confirmed by several platinum 

 determinations in platinum compounds obtained from these substances. These 

 results appear to indicate the existence of a series of bases having the general 

 formula C re H 2re _ 3 N. The further investigation of these substances would be of 

 interest, but as they are obtained only in minute quantity, and are clearly 

 secondary products of the action of sodium on pyridine, it is scarcely possible to 

 obtain them in sufficient quantity for this purpose. 



At the beginning of this paper, mention has been made of a black or dark-gray 

 substance, obtained in the second process for preparing dipyridine. This com- 

 pound was only obtained towards the close of the investigation, and I have not 

 had time to examine its properties and relations minutely. It is a black 

 amorphous powder, quite insoluble in water. When exposed to the air, it is 

 rapidly converted into a mass of crystals of pure dipyridine. I was at first 

 disposed to consider this substance to be a sodium compound of dipyridine, but I 

 soon found that this was not the case, and that its properties more nearly corres- 

 ponded with a hydrogen compound of that base ; and it seems probable that its 

 formula will turn out to be C 10 H 12 N 2 , in which case it would be related to 



