Quarterly Meeting, October 16th, 1860. 
Dr. R. Angus Smith, Vice-President, in the Chair. 
The Chairman gave a short account of his examination 
of coal pyrites for arsenic. He stated that although the 
knowledge of the existence of arsenic in the iron pyrites 
found in coal may not be considered perfectly novel, it cer- 
tainly does not seem to be known that arsenic is so widely 
disseminated as to form an ordinary constituent of the coals 
burnt in our towns, and chemists of celebrity have held it — 
and now hold it — to be absent there. He had examined 
fifteen specimens of coals in Lancashire, and found arsenic in 
thirteen. He had also found it in a few others; but Mr. Binney 
having promised a collection, properly arranged, the examina- 
tion will then be made more complete. Mr. Dugald Campbell 
had also lately found arsenic in coal pyrites. The Chairman 
added, that this had a very direct bearing on our sanitary 
knowledge, as we must now be obliged to add arsenic to the 
number of impurities in the atmosphere of our large towns. 
It is true that he had not actually obtained it from the 
atmosphere, but when the pyrites is burnt the arsenic burns 
and is carried off along with the sulphur. One or two coal 
brasses (as they are called) contained copper, a metal that is 
also to some extent volatilized, as may be readily observed 
wherever copper soldering takes place. Although an 
extremely small amount of copper is carried up from furnaces, 
it is not well entirely to ignore it. The amount of arsenic, 
however, is probably not without considerable influence, and 
we may probably learn the reason why some towns seem less 
affected than others by the burning of coals, by examining 
the amount of arser : n burnt as well as sulphur. 
Proceedings— Lit. & Phil. Society— No. 2.— Session, 1860-61. 
