PREVENTION OF MARSH FEVER. 407 
of M. Martinet may consult ( The Comptes Rendus,’ No. 20, 
(Nov. 1854), p. 974. 
[Not long since we visited the Copper-Smelting works at 
Swansea, for the purpose of adding, if we could, to the facts 
already known respecting the peculiar ossific diseases to 
which horses and cattle are liable, in that locality, caused 
by the disengaged vapours. We ascertained that ophthalmia 
is not so prevalent an affection there as it has been stated to 
be ; and, from what we saw, we were induced to refer the 
production of the singular state of the osseous tissue and 
joints rather to the inhalation of the vapours, than to their 
becoming deposited on the grass, and thus being taken into 
the system with the food. 1st— Because all around, and to 
a very great distance from the works, there is nothing to be 
seen but extreme barrenness. 2d — We believe the vapours 
to be of such a character, that only to a certain distance 
could they ordinarily be borne by the winds, and then 
falling, they would destroy all the vegetation on which they 
might rest. 
Dr. Shsefhauetl brought these vapours in contact with 
steam, and subjected them to great pressure, by which he 
obtained a solid compound, in the form of beautiful crystal- 
line leaves, consisting of — 
Arsenious Acid 68*250 
Sulphuric Acid 27*643 
Protoxide of Iron 3*029 
Oxide of Copper 0420 
Oxide of Nickel 0*656 
Loss 0*002 
100 * 
We were informed of the exemption of the workmen from 
attacks of cholera during the time this disease prevailed in 
the neighbourhood, and which we felt disposed to attribute, 
not to the disengagement of arsenious acid, but rather to the 
sulphurous acid that accompanies it, and which acts as a 
disinfectant by decomposing the fetid binary compounds of 
hydrogen, especially sulphuretted hydrogen. If two volumes 
of this gas be mixed with one volume of sulphurous acid, 
they mutually decompose each other, forming water, and 
throwing down the sulphur; although Thompson says it is 
not sulphur, but a compound of that substance with oxygen 
and hydrogen, which he calls hydro-sulphurous acid. Or, 
should it be that the sulphurous acid becomes converted into 
the sulphuric, this would also effect its decomposition, and 
the results would be the production of water, sulphurous acid, 
