384 RELATIVE ATTRACTIONS OF 
often exceeds 80°; and we find that the aerial 
space of the chambers is capable of receiving from 
the liquid on the floors four or five times a greater 
weight of aqueous vapour in summer than in 
winter, and of transferring it, in a proportionately 
accelerated rate, to the newly formed combination 
of gases voracious to receive it. Then, since an 
abundant supply of aqueous vapour is indispen- 
sable to the speedy conversion of sulphurous 
acid, by nitrous acid, into sulphuric acid, and since 
the capacity of space for vapour not only increases 
with an increase of temperature, but even in- 
creases in an increasing ratio as the temperature 
rises, how can it be otherwise than extremely evi- 
dent that as much sulphur cannot be converted 
into sulphuric acid, in the same chamber room, 
and in a given time, in winter as in summer? 
When the attempt to effect such an object is made, 
the consequence is, that large portions of the 
gases pass through the whole range of chambers, 
and at length escape by the outlet into the exter- 
nal atmosphere, without being condensed; and, 
indeed, as sulphuric acid chambers are usually 
managed, a great amount of the gases must in 
winter be lost in this manner; for, when the tem- 
perature of the atmosphere is low, the operator 
finds a difficulty in keeping the temperature of 
