690 MEMOIRS OF A VETERINARY SURGEON. 
Thirdly. The different method of medical treatment which 
is now adopted whenever disease makes its appearance. 
It is not my province, or even my intention, to dilate to 
any great extent upon the two former causes of the improved 
state of things; the first is, I think, too self-evident to need 
a moment’s comment, and for this our thanks are due, in a 
great measure, to the example and also to the impetus which 
has been given by the different agricultural associations. 
The second consists very materially in the improved con¬ 
struction of our stables. They are loftier and more roomy, 
ventilated more in accordance with common-sense rules, and 
drained more effectually. Besides, more attention is now 
paid to cleanliness, and also to the temperature of the build¬ 
ing. And here let me not forget to mention the important 
benefit which accrues from the employment of the disinfectant 
powder of Mr. McDougal. This agent not only destroys the 
deleterious and noxious emanations which arise, but it tends 
likewise to lower the temperature in heated stables, and to 
cause a total absence of flies, thus enabling the horse the 
better to rest. By the escape of a small proportion of car¬ 
bolic-acid gas, which is eliminated during the process of 
its action, it also contributes in some manner to those ex¬ 
tremely mystical and delicate conditions of the atmosphere 
that render it in itself more conducive to health. In reference 
to this subject, I think I cannot do better than give the 
modus operandi of the agent in the words of the patentee, 
who has kindly favoured me with the following description: 
<f The manner in which the chemical condition of the 
atmosphere is affected, by the use of this disinfecting agent, 
is both interesting and curious. All our previous notions 
have been, that a substance to combine with the gases 
formed during the process of putrefaction was the only thing 
required; the one in question, however, while it fulfils this 
condition, is chiefly designed to prevent fermentation and 
the consequent evolution of gaseous products. When a 
stable is closed for the night, its occupants may be considered 
as limited for oxygen for the arterialization of the blood, 
through the small quantity contained in the air of the stable, 
with any additions which may be made to it by means of 
ventilation. 
(C The deterioration of the air goes on continuously—the 
animals always spiring a smaller quantity of oxygen, and a 
larger quantity of carbonic acid than was inspired—therefore 
the oxygen becomes less, and the carbonic acid greater. But 
the process is greatly increased by another cause—the ex¬ 
pired air is always charged with organic matter from the 
