CN PROXIMATE CONSTITUENTS OF COAL. 345 
Although the action of hydrochloric acid and potassium chlorate on 
the coal is a slow one, it is much more thorough in its attack than other 
oxidising agents tried. The coal left after treatment and removal of 
oxidised product with acetone, when submitted to a second treatment 
with acid and chlorate of potash, is still further attacked and converted 
into products similar to those formed in the first instance, and it appears 
that the proportion of oxidised product increases with each successive 
oxidation. To study the mode of action, 10 grams of the coal were boiled 
with dilute acid and 20 grams of chlorate of potash, added in small 
quantities at a time; the action continued for forty-four hours. The 
dried product was found to have increased by 21 per cent. in weight, and 
of this 62:7 per cent. was dissolved by acetone. The residue left after 
treatment with acetone weighed 5:27 grams, which was again oxidised for 
forty hours. Of the dried product 74 per cent. was removed by acetone, 
and the remaining 1°26 gram, after a third and similar treatment, gave a 
product from which acetone dissolved some 77°8 per cent., leaving 
0-32 gram of coal-like insoluble residue. 
The analysis of the coal after it had been treated four time with these 
reagents shows an increased percentage in carbon and hydrogen and the 
presence of a trace of chlorine. 
From the above it is evident that the coal substance is powerfully 
attacked by hydrochloric acid and potassium chlorate, but the products of 
this action are for the most part complex substances, from which at 
present but little information can be derived as to the nature of the 
materials from which they are formed. These bodies appear to be acidic 
in properties, and form dark brown solutions with caustic alkalis and 
ammonia, from which metallic salt solutions, such as barium chloride, 
lead nitrate, silver nitrate, &c., precipitate out dark coloured gelatinous 
salts, which are difficult to obtain in a state of sufficient purity for 
analysis. The attempts to obtain information as to the constitution of 
these chlorinated compounds have up to the present yielded no-satisfactory 
results. 
The composition and physical properties of these chlorinated com- 
pounds recall those described by Messrs. Cross and Bevan in their inves- 
tigations of jute—for example, the substance described by these authors as 
tetrachlorobastin (C3,H,,Cl,0,,), from which they have obtained proto- 
eatechuic acid by fusion with potash. 
The treatment of cannel coal with hydrochloric acid and potassium 
chlorate results in the production of compounds similar to those obtained 
from the coal of the Hutton seam ; the oxidation product soluble in alcohol 
contained some 24-13 per cent. of chlorine. 
A sample of bitumen submitted to a similar treatment gave a product 
from which ether dissolves about two-thirds, the ethereal solution on 
evaporation leaving a dark viscous residue, which was found to contain 
11:06 per cent. of chlorine. 
Whilst postponing for the present the further study of these chlorinated 
compounds, Mr. Smythe has begun the investigation of the action of 
hydrochloric acid and potassium chlorate in ‘brown coal.’ For this 
purpose samples of brown coal were obtained from Brihl, near Cologne : 
this variety of coal is much more readily attacked than the coal from 
Durham. It is also noteworthy that whilst the dry oxidised product from 
the latter weighs more than the coal, in the case of the brown coal there 
is a notable decrease in the weight. Further, there is a much larger 
