'M Injurious Manufactories. 
The sulphuric acid is obtained by the combustion of a 
mixture of sulphur and nitre. It is very difficult in this 
process to prevent a more or less observable smell of sul- 
phurous acid from being diffused around the apparatus, 
in which the combustion is performed ; but in manufac- 
tories skilfully conducted this smell is scarcely percepti- 
ble within the building itself, is not dangerous to the 
workmen who respire it daily, and can give no reasona- 
ble foundation for complaint to the neighbours. When 
the art of making sulphuric acid was introduced into 
Franee, the public opinion was strongly expressed 
against the first establishments for the purpose ; the 
smell of the match with which we kindle our fires con- 
tributed not a little to exaggerate the effect that must be 
produced by the rapid combustion of several hundred 
weight of brimstone ; but men’s fears on this head are 
now so much allayed, that we see several of these ma- 
nufactories prosper in peace in the midst of our cities. 
The distillation of aqua fortis and spirit of salt, in 
other words, of the nitric and muriatic acids, are not 
more dangerous than that of sulphuric acid. The whole 
of the process is performed in an apparatus of glass or 
earthen-ware, and it is unquestionably the great interest 
of the manufacturer to diminish the volatilization or loss 
of the acid as much as possible. Yet, let him pay what- 
ever attention he will to this, the air breathed in the ma- 
nufactory is always impregnated with the smell peculiar 
to each of these acids ; but you may respire there freely 
and safely, the men who work in it daily are not at all 
incommoded by it, and the neighbours would be very 
much in the wrong to complain. 
Sinee the manufactories of white lead, of verdigris, 
and of sugar of lead, have increased in France, the de- 
mand for vinegar has been enlarged. 
When this acid is distilled, to fit it for some of the 
