198 
MEMOIRS OF A VETERINARY SURGEON. 
water, and medicine appropriate to such cases. This is one 
of the results of more enlightened times, and proves him 
to be a man who has had instilled into him the immense 
value and importance of taking time by the forelock. 
The disease is only in its incipient stage . 
INFECTED STABLES. 
It sometimes occurs that we find more disease in one 
stable than in another; it is then our bounden duty to bring 
into play all our powers of observation. In the first place 
we should note whether the stable be properly ventilated, 
sewers thoroughly cleansed, the stalls properly swept 
under the manger, and the disinfectant powder used ; we 
should also bring the thermometer into requisition, to 
observe the maximum and minimum temperature ; and ascer¬ 
tain the exact state of dryness, or humidity of the air by 
means of the hygrometer, and compare it with the hygienic 
state of other stables. 
THE HYGROMETER. 
This scientific instrument is for the purpose of indicating 
the relative degrees of dryness or humidity in the atmosphere, 
as well as its temperature. There are two perpendicular 
glass tubes, with a bulb at the bottom of each, containing a 
quantity of quicksilver. It may very properly be called a double 
thermometer. There is likewise a graduated scale along the 
side of each tube. The bulb of one tube is encased in a fine 
linen or silken bag, one end of which is immersed in pure 
soft water in a glass cup; the water soon ascends, by the law 
of corpuscular or capillary attraction, to the top of the bag 
surrounding the bulb. The evaporation which goes on from 
the bag upon the surface of the bulb robs the quicksilver of 
a certain amount of heat, in exact proportion as the evapora¬ 
tion is rapid or slow, and this effect is dependent upon the 
state of humidity or dryness of the surrounding air. When 
the air is very dry, the difference between the two thermo¬ 
meters will be very great; if it be moist, the difference will be 
less in proportion, and if the air be fully saturated, the two 
thermometers will stand alike. 
My experience has fully convinced me that we do not pay 
that amount of attention to these points which we ought, and 
which their importance demands. Observe the low, typhoid, 
lingering class of cases that we have in wet, damp seasons, 
of unusual duration. 1 do not know of one single bodily 
