Injurious Manufactories . 
ought to be removed to a distance from the dwellings of 
men. 
There is a very important observation to be made on 
the spontaneous decomposition of animal substances* 
which is* that the emanations from them appear to be so 
much the less dangerous* as the substances whieh under- 
go putrefaction are less humid : in the latter case* a con- 
siderable quantity of carbonate of ammonia is evolved* 
which imparts its predominant character to the other 
matters volatilised* and corrects the bad effects of such 
as are deleterious. Thus the decomposition of stercora- 
ceous matters in the open air* and in places the situation 
and declivity of which allow the fluids to drain off* and 
that of the refuse of the cocoons of the silk-worm evolve 
a vast quantity of carbonate of ammonia* which corrects 
the virus of some other emanations ; while the very same 
substances* decomposed in water or drenched with this 
fluid, exhale sweetish and nauseous miasmata* the respi- 
ration of which is very dangerous. 
The numerous arts in which the manufacturer produces 
and diffuses in the air* in consequence of his processes 
and by the help of fire* vapours more or less disagreea- 
ble to breathe* constitute the second class of those we 
have to examine. 
These* more interesting than the former* and much 
more intimately connected with the prosperity of our na- 
tional industry* are still oftener the subject of complaints 
brought before the magistrate for decision* and on this 
account have appeared to us to require more particular 
attention. 
We will begin our examination with the manufacture 
of acids. 
The acids that may excite complaints of the neigh- 
bours against their preparation are the sulphuric, nitric* 
muriatic* and acetous. 
