ON PROXIMATE CONSTITUENTS OF COAL. 341 
In 1874 Dondorff drew attention to the occurrence in several West- 
phalian gas coals of a blackish solid, with a reddish brown colour in 
reflected light, having a brown streak. This substance is found in thin 
leaflets on this coal, and is almost entirely soluble in ether, forming a 
light yellow solution, which fluoresces not unlike solutions of the salts of 
quinine. 
By the extraction of a Westphalian gas coal with ether Muck has 
obtained an ethereal solution of a similar character, and from it obtained 
a solid of the following percentage composition :— 
C=87:22, H=9-20, O=2:29, S=1-29 (nitrogen absent). 
This substance, when heated in a platinum crucible, leaves a coke-like 
residue, amounting to 32:09 per cent. The author considers this substance 
to be widely diffused in coal, and has shown it to exist in varying amounts 
in different parts of the same seam. Associated with this investigation is 
that of P. Siepmann, who has submitted the gas coal of the Pluto mine, 
Westphalia, to a systematic extraction with chloroform, ether, and alcohol, 
ebtaining the following results :— 
The chloroform extract amounted to 1:25 per cent. of the coal ; the 
solution, dark yellow to brown in colour, possessed a strong green fluo- 
rescence ; the composition of the extract was 
C= oe ht—7-95, O—A-27 N27 baila. 
The residue, after extraction with chloroform, gave, when treated with 
ether, a light yellow solution having a bluish green fluorescence, from which 
a solid was obtained amounting to 0:3 per cent. of the coal, and containing 
C=84'82, H=10°51 and O= 4°67. 
The residue treated with alcohol gave a solution similar in character 
to the ethereal solution, The amount removed by the alcohol was 0:25 
per cent. of the coal, and the composition of the dissolved solid was found 
to be 
C=72:52, H=10-08, O=17°4. 
After the above treatment the residual coal was again extracted with 
chloroform, which removed 0:75 per cent. of the coal, and left on evapo- 
ration a dark brown, pitch-like mass, which gave the following results on 
analysis :— 
C=78'82, H=8-56, O=9:97, N (trace), S=2°65. 
The last chloroform solution was dark brown in colour and feebly 
fluorescent. 
“1 ips composition of the coal before and after this treatment is given 
elow :— 
Cc H oO a ON, 
Before treatment ‘ : Rats (033 5°50 12°94 1°25 
After treatment . > : = . 74:00 4:77 20:09 114 
According to H. Reinsch, alcohol extracts from coal a substance sup- 
posed to be altered ‘chenopodin,’ a body which the author had discovered 
in the sap of Melilotus albus, and to which he attributes the composition 
C,.H,;0,N. In 1885 P. Reinsch concluded that coal consists of two 
