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7 
DESTRUCTIVE DISTILLATION OF ANIMAL MATTERS. 573 
that, if a mixture of two such bases were partially saturated by an acid, the salt 
produced should consist chiefly of the stronger base, and consequently should 
give a large excess of hydrogen. Salts prepared in this way gave the exact 
results required for pyridine, as will be seen in a subsequent page. 
Pyridine and its Compounds. 
In the second part of this paper a very cursory account was given of pyridine 
and its platinum salt, at a time when I had obtained this beautiful base in com- 
paratively small quantity. Subsequent experiments have afforded me a much 
larger supply, and rendered it possible to submit it and its compounds to a more 
minute investigation. It is a transparent and colourless oil, with a powerful 
pungent smell, soluble in water in all proportions, and obtained absolutely dry 
only with some difficulty. It boils at 242°, and its specific gravity at 32° F. is 
09858. It precipitates the salts of zinc, iron, manganese, and alumina in the 
cold, nickel only on the application of heat, and the precipitate dissolves in 
excess. Copper gives a pale blue precipitate, soluble in excess of base with a 
deep blue colour, not distinguishable from that produced by ammonia. It has a 
remarkable tendency to form double salts, most of which are highly crystallizable, 
and retain the metallic oxide in a state in which it cannot be precipitated by 
excess of pyridine. An analysis gave— 
3°175 grains of carefully dried pyridine gave 
8°830  ... carbonic acid, and 
1-950 ... water. 
Calculation. 
Carbon, Z : 5 . 75°84 75:94 C, 60 
Hydrogen, . : ; : 6°82 6°33 H, 5 
Nitrogen, . j ‘ 4 ahs 17:73 N 14 
100-00 79 
The density of the vapour of pyridine determined by Dumas’s method, gave— 
I, II. 
Temperature of the air, . ; : 14° cent. 15° ¢. 
ie vapour, . |) 16455, 143° 
Excess of weight of the balloon, - 0°3088 grammes. 0-4060 gr. 
Capacity of the balloon, : - 305 ¢.¢. 324 ¢. ¢. 
Barometer, . , ; : 765 m. m. 752 m. m. 
Residual air, 2 . s , 14 «Ge, a 
Density of vapour, . : 5 2:912 2°920 
The formula C,, H; N requires 
10 vol. carbon vapour = 0°8290 x 10 = 8-2900 
10 ... hydrogen... =0°0692 x 10 = 0°6920 
2... nitrogen ... = 09713 x 2 = 1:9426 
10 9246 
