SULPHURIC ACID FOR WATER. 387 
water, into the chambers*: this must have a 
particularly beneficial effect, when the tempera- 
ture of the chambers would otherwise have been 
as low as I have just alluded to, but it has also 
disadvantages: its beneficial effect cannot last 
much longer than during the time the steam is 
allowed to enter the chambers ; and it is impru- 
dent to allow it to do so long, because the great 
cooling power of the chambers causes the steam 
to condense nearly as quickly as it enters ; and by 
continuing to admit it, the acid on the floors would 
soon become much diluted; the consequence of 
which would be, that the manufacturer would have 
* Though steam is sometimes thus used, it is not because 
those who use it have a correct knowledge of the great im- 
portance of the continual generation and existence of steam 
(in the scientific acceptation of the term, invisible vapour) in 
the chambers. They use it, from the understanding that it— 
steam of 212°, or thereabout—must necessarily be condensed 
on entering the cold chambers; and in the resulting water 
falling as rain or fog, the gases readily meet with the water 
dispersed for their action—the condensed steam, therefore, 
carrying the sulphuric acid down along with it ;—nor do they 
seem to be aware of the fact, that if the temperature of the 
interior of the chambers was so high as to hold (supposing 
the absence of acid and the gases) in an uncondensed and 
invisible state the steam admitted, that even then the gases 
would, if admitted, supply themselves from that steam with 
the requisite water, and that strong liquid acid would fall, 
though the temperature might be great enough to retain pure 
water in the state of invisible steam. 
