DESTRUCTIVE DISTILLATION OF ANIMAL MATTERS. 585 
Temperature of the air, 5 é é é 17° cent. 
vai vapour, . 3 , , XS 5 
Excess of weight of the balloon, : ‘ : 0-4493 grammes. 
Capacity of do. - i ; ‘ 302 ¢, ¢, 
Barometer, : S : ? : 776 m. m, 
Residual air, ‘ k é : : 0 
Specific gravity of the vapour, : : ‘ 3°839 
The formula C,,H,N requires 
14 vol. carbon vapour, 
18 vol. hydrogen, 
2 vol. nitrogen, 
0:8290 x 14=11-6060 
0:0692 x 18= 1:2456 
0:9713 x 2= 1:9426 
14°7942 
et) 
4 
Heit al 
In the following table I have collected the whole of the data, all having been 
carefully redetermined with much purer materials than those used in my ori- 
ginal experiments,— 
Specific Gravity. 
Specific 
Volume 
Vapour. | Liquid at 32° at 32°. 
Formula. | Boiling Point. 
Pyridine, C,,H,N | 242° 2-916 0:9858 80-1 
Picoline, CN | 275° 3-290 | 0-9613 96-7 
Lutidine, C,,H,N 310° 3-839 0:9467 113-0 
Collidine, O/H Net) 856° ts 0:9439 128-2 
The boiling points of pyridine, picoline, and lutidine agree remarkably well 
with Kopr’s law, but collidine differs very materially from it. Less reliance, 
however, is to be placed upon the boiling point of the last substance, as it was 
determined upon a very small quantity of material. The specific gravities of the 
vapours agree very closely with theory, while those of the fiuids themselves, 
taken at 32°, illustrate also in a very remarkable manner the gradual diminution 
which is observed when we ascend through a series of homologous substances. 
To these experimental numbers have been added the specific volumes of the bases 
at 32°, calculated from the data they afford: but no determinations of the co- 
efficient of expansion of these substances having been made, it is not possible 
to ascertain their specific volumes at the boiling points, although from the rapidity 
of their expansion, I believe it will be found that the difference must approach 
very closely to 22, which is that produced in non-nitrogenous substances by the 
addition of C,H, to their atom. 
