POSTSCRIPT. 
Although the analogy existing between picoline and the other oleaginous 
bases is perfectly sufficient to warrant the assumption of the absence of oxygen 
in that substance, I have thought it advisable to append here an experimental 
determination of the nitrogen. As the volatile bases cannot be readily analysed 
by VARRENTRAP and WILL’s method, I made a combustion of the platinum salt, 
and determined the proportion by volume of the carbonic acid and nitrogen in 
four tubes, which gave the following results :— 
I. 94 volumes gave 8: nitrogen. 
II. 240 Be: 18: 
Ill. 84 aad 6°5 
IV. 421 oars 35° 
839 67:5 
These results give the gases in the proportion of 114 to 1; in other words, 
they shew a slight excess over the theoretical result, according to which they 
should be in the proportion of 12 to1. They confirm perfectly, however, the 
absence of oxygen. 

