50 
With respect to the question more immediately under 
discussion, he might say that he had frequently observed two 
distinct descriptions of coal, or rather a combination of 
sulphur with coal, which he had perhaps very erroneously 
considered a chemical and mechanical combination between 
sulphur and coal, and that observation would bear on what 
Mr. West had said, in having thrown out such pieces of coal 
as he found to contain sulphur visible on the exterior. He 
could speak practically to the point, that the coal which was 
used for making iron, in that part of Yorkshire in which he 
resided, exhibited a large quantity of sulphur on the exterior, 
but in coking the coal, nearly the whole of it w^as expelled, 
and the coke made a very excellent iron. They had other 
coals which exhibited no appearance of sulphur or iron 
pyrites, but in reality did contain a very large portion of 
sulphur, which he had supposed to be chemically combined. 
But the coal in question, which exhibited no sulphur, had so 
much in it that no treatment could make it suitable for the 
making of iron. This supposition might or might not be 
correct, — he merely took the liberty of suggesting it, in order 
that it might be of some use to the society on this exceedingly 
interesting subject. 
Mr. West remarked that the proportion he found in coke 
was 196 in 10,000, which would be equivalent to 98 in the 
coal. In two or three cases of coking, where he had the 
best opportunity of judging of the coal, the proportion would 
probably be one half. 
The Chairman inquired of Mr. West whether he had 
thought of any chemical process by which the sulphur might 
be got rid of to a greater extent ? 
Mr. West said he had reflected on the subject, but in- 
stead of trying any further experiments, he thought a change 
of coal w^ould be desirable. 
Mr. Hartop observed that in practice (it might be che- 
mically wrong) a large quantity of water was poured on the coke 
