328 
M. STALKER. 
SOME OBSERVATIONS ON CONTAMINATED WATER SUPPLY 
FOR LIVE STOCK* 
By Dr. M. Stalker, V.S., Ames, Iowa. 
There is no fact better known to the sanitarian than that 
one of the chief sources of danger to life and health is the 
contamination of drinking water. If a malignant form of 
fever makes its appearance in a family, which cannot be ex¬ 
plained by the history of actual exposure to contagium, the 
water supply always comes in for an early and liberal share 
of attention. The instances are sufficiently numerous in 
which the investigator is enabled to trace the malady to this 
source, to warrant every reasonable precaution in procuring 
a pure water supply. Nor are these facts known to the sani¬ 
tarian alone. The reading public have been sufficiently 
enlightened on this subject to enable them to avoid much of 
the danger from this source. While we are beginningto take 
a fairly lively interest in our personal dangers and the methods 
calculated to avert them, we have yet hardly taken time to 
consider the economic question of how far our live stock in¬ 
dustry may be affected by the same class of causes. We 
drill down into the solid rock to procure a water supply of 
unquestioned purity for family use. We boil, or subject to 
other purifying means, all suspected samples before they can 
be used. This is well. But all this time our helpless dumb 
creatures may be compelled to drink from a shallow slough, 
foul with decomposing vegetation, or from a surface pond 
almost at boiling temperature under a summer sun, where 
the minute forms of animal and vegetable life gender in such 
profusion as to render the whole a mass of animate slime. 
No one who has had a glimpse of the microscopic world 
would except a human being to take a draught of such a 
beverage and live. But our animals are not only expected 
to live, but to thrive under such conditions. That these ex¬ 
pectations are frequently disappointing, I will cite an instance 
♦Extract lrom Bulletin Iowa Agricultural Experiment Station, Ames, Iowa. 
