172 
“Corrections of the Nomenclature of the objects figured 
in a memoir ‘ On some of the Minute Objects found in the 
Mud of the Levant/ &c., published in Yol. VIII. of the Me- 
moirs of the Litei'ary and Philosophical Society of Manches- 
ter,” by Professor W. C. Williamson, F.R.S. 
“On Arsenic from Alkali Works,” by H. A. Smith, F.C.S. 
Communicated by Professor H. E. Roscoe, F.R.S. 
Some time ago the author laid before the Society the 
results of several analyses of the amounts of arsenic con- 
tained in different species of pyrites, and in several of the 
products in the manufacture of which the acid was employed 
At that time he carried his analyses as far as the carbonate 
of soda, in which no arsenic was found. The present paper 
is supplementary to the former, and he now endeavours to 
to show that not only does the arsenic remain in the 
various products of alkali manufacture but even escapes to 
the atmosphere. 
When the salt used for the production of Hydrochloric 
acid is treated with Sulphuric acid, containing Arsenic, the 
Arsenic present becomes converted into the trichloride. 
This compound is said to be completely decomposed by 
contact with water, so that, after passing along with Hydro- 
chloric acid gas through the condensing towers, it would 
scarcely be expected that any traces of the Arsenic originally 
present would be found in the escaping gas. The author 
finds this, however, to be the case. A considerable quantity 
of the Arsenic trichloride escapes the action of the water in 
the condensing towers, and passes, along with a very small 
proportion of the Hydrochloric acid gas, to the chimney. 
A deposit found in the flue, about 20 feet long, leading 
from the saltcake furnace to the condensing towers ; the 
coke contained in the towers themselves ; the gas in the 
Hue leading to the chimney ; and the smoke escaping to the 
chimney were all submitted to analysis, and were all found 
to contain arsenic. 
