628 
VENTILATION. 
it is easy to conceive how very valuable such statistics would 
be in deciding cases in dispute. 
I trust I shall not be considered presumptuous in sug¬ 
gesting a few points for consideration, when searching for 
the cause of similar lesions to the one in question. The age 
of the horse must be particularly borne in mind. If he is 
young, congenital peculiarities may be looked for; or if old, 
or even middle aged, the coats of the veins may be unnaturally 
thin, and brittle. Such an altered condition of their coats 
may also be accompanied with varicosity. The varix may be 
confined to one side of the vein only, which may arise from 
its inner lining membrane bulging out between the fibres of 
the muscular coat, this constituting hernia. Impediments 
to the free circulation of the blood near to the parts where 
the lesion may take place, or even remote from it, would 
predispose to such ruptures, and especially would this be the 
case if the coats of the vessels had been weakened by pre¬ 
vious disease. 
A long, interesting case of varicosity of the posterior vena 
cava was published in the Veterinarian for 1856, vol. xxxi, by 
Mr. W. A. Cox, of Ashbourne. 
Such are some of the points which suggest themselves to 
me as being worth bearing in mind when looking for the 
cause of such lesions as the above. 
VENTILATION. 
A Paper read before the “ Army Veterinary Medical Associationf 
Aldershot , on Wednesday , August Zlth, 1862. 
By T. W. Mavek, Esq., M.E.C.V.S., V.S., B.A. Train. 
Gentlemen, —In a paper which I had the honour to read 
before this association during our last session I endeavoured 
to show how the preservation of animal life had been pro¬ 
moted by the application of veterinary science, and stated 
that one of the most important means by which this de¬ 
sirable result had been obtained was by securing the quality, 
and regulating the quantity, of atmospheric air supplied, by 
a well-constituted system of ventilation. 
By reference to certain calculations and experiments which 
have already been made in connection with this important 
subject, I endeavoured to demonstate that, although attempts 
had been made to establish in our stables a better system 
