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weeks. The Second class includes those that are not tuberculous but 
which show an elevation of temperature as a result of («) advanced 
pregnancy; ( b ) the excitement of oestrum; (c) concurrent diseases, 
as inflammation of the lungs, intestines, uterus, udder, or other parts, 
abortion, retention of afterbirth, indigestion, etc.; ( d ) inclosure in a 
hot, stuffy stable, especially in summer, or exposure to cold drafts or 
rains, or ( e ) any change in the method of feeding, watering, or 
stabling of the animal during the test. 
Notwithstanding all these possibilities of error, the results of thou- 
sands of tests show that in less than 3 per cent of the cases tested 
do these failures actually occur. In the first class the chances of error 
are decidedly reduced by the skilled veterinarian by making careful 
physical examination and diagnosing these advanced cases, and by 
the injection of double or triple doses into all recently tested cattle, 
with the taking of the after temperatures beginning two hours fol- 
lowing the injection and continuing hourly for twenty hours. In 
the second class errors are avoided by eliminating those cases from the 
test that are nearing parturition or are in heat, or show evidence of 
the previously mentioned diseases, or exhibit temperatures sufficiently 
high to make them unreliable for use as normal. Then, in reading 
after temperatures it is advisable not to recognize as a reaction an 
elevation of temperature less than 2° F., or one which at the same 
time does not go above 103.8° F., and the temperature reaction must 
likewise have the characteristic rainbow curve. (Those cases which 
approximate but do not reach this standard should be considered as 
suspicious and held for a retest six weeks later.) In addition, a satis- 
factory tuberculin must be used ; also an accurate thermometer and a 
reliable syringe in order that a sufficient dose of tuberculin may be 
given. Finally, the number of apparent errors of the tuberculin test 
will be greatly diminished if a careful post-mortem examination is 
made, giving especial attention to the lymph glands. 
This low percentage of failures being the case, cattle owners should 
welcome the tuberculin test not only for their own interest but for 
the welfare of the public as well. Where this method of diagnosing 
the disease has been adopted tuberculosis is gradually being eradi- 
cated, while it is spreading rapidly and becoming widely disseminated 
in those districts where the tuberculin test has not been employed. 
Without its use the disease can not be controlled and the cattle owner 
is confronted with serious and continuous losses; with its use the dis- 
ease can be eradicated from the herd, a clean herd established, and 
the danger of its spread to man removed. Tuberculin may, therefore, 
be considered a most beneficial discovery for the stock raiser. Strange 
to say, many of these men have been incredulous, antagonistic, or 
prejudiced against the tuberculin test by misinterpreting published 
