i6 Injurious Manufactories. 
Some preparations extracted from animal substances 
require the putrefaction of these substances, as in the fa- 
brication of catgut ; but it is more frequently the case, 
that animal substances employed in manufactures are li- 
able to putrefaction from being kept too long, or exposed 
to too great warmth, as we particularly find in dyeing 
cotton red, a process in which a large quantity of blood 
is employed. The miasmata exhaled by these putrid 
matters spread far round, and form a very disagreeable 
atmosphere for all the neighbourhood to breathe ; it is 
the part of a good government, therefore, to cause these 
substances to be renewed so as to prevent putrefaction, 
and the manufactory to be kept so far clean, that no re- 
fuse of the animal substances employed shall be left to 
rot in them. 
In this last point of view slaughter-houses exhibit 
some inconveniencies ; but they are not of sufficient im- 
portance to require them to be placed without the pre- 
cincts of towns, and assembled together in one spot, as 
speculative men are daily proposing to government. A 
little attention on the part of the magistrate, to prevent 
butchers from throwing out the blood and refuse of the 
beasts they kill, would be sufficient to remedy complete- 
ly every thing disgusting or unhealthy arising from 
slaughter-houses. 
The fabrication of poudrette (night-soil dried) begins 
to be established in all the large towns of France, and 
the operation by which excrementitious substances are 
reduced to this state, necessarily occasions a very disa- 
greeable smell for a long time. Establishments of this 
kind therefore ought to be confined to airy places, remote 
from any habitation ; not that we consider the aeriform 
exhalations from them as injurious to health ; but no one 
can deny, that they are incommoding, noisome, disagree- 
able, and difficult to breathe, on all which accounts they 
