ON VETERINARY HYGIENE. 
591 
minated have remained uncorrected. One great source of impu- 
rification is the breath. A dozen or twenty horses, standing side 
by side or croup to croup, require a continual renewal of the air 
presented to their nostrils : air lacking oxygen, and charged with 
carbon, cannot but be offensive, if not positively injurious, to the 
delicate sensitive membrane lining both the air-passages and lungs; 
to say nothing about the harm done the animal system through 
interruption to the requisite changes in the blood. Proper ven- 
tilation provides against this, and thus all mischief from such a 
source is anticipated. 
But there is another source of impurity — if not a greater or 
more harmful one, still one of acknowledged evil, and one against 
which, so far as we know concerning it, there is every reason that 
we should endeavour to efficiently protect the animal — and that is, 
the effluvium from the urine and dung of the animal, and in parti- 
cular the former. It will be said, perhaps, that drains carry away the 
urine, and that the dung is no sooner dropped than it is removed 
out of the stable. We would remind those persons, however, who 
may sit down satisfied that no harm can arise from such sources 
in stables which are drained and kept clean, that in these stables 
stench, even to a greater degree, is likely to be generated from the 
dispersion of the urine upon the floor — seeing that males and 
females cannot both stale through the same barred receptacle in 
the stall. And, even supposing such was the case, the cesspool 
underneath the barred grating never ceases to emit urinous effluvia, 
though such may be more evident immediately after staling, or 
any agitation of the contents of the cesspool, than at other times. 
In a stable where the drain and receptacle for the urine is behind 
the horse there must be necessarily a greater dispersion of the 
fluid upon the floor, and a corresponding amplitude of surface for 
unwholesome evaporation. The stable, however, which of all 
others appears to generate this urinous atmosphere is the one un- 
furnished with any drain or receptacle for the urine ; wherein it is 
suffered either to diffuse itself over the flooring and disappear 
through being absorbed by the soil in the interstices of the pave- 
ment, or by the pores of the pavement itself (such as wood), or 
else through evaporation from the wetted unabsorbent surface. In 
either case urinous vapours will arise in abundance. 
