THE TUBERCLE BACILLUS 609 



of NaCl and adding distilled water to isotonicity. Craig, Bronfenbren- 

 ner and the above-named writers have reported good results with 

 these various antigens, and, although it is too early to say which will 

 prove most useful, it is clear that complement fixation methods can aid 

 in the diagnosis of active tuberculosis. We can, of course, judge con- 

 cisely only of the method used in our laboratory, where Miller has 

 followed carefully a considerable number of cases on which the method 

 has been used. It would appear at present that about 70 per cent 

 of the fixation results correspond with clinical findings. 



The Tuberculin Test as Applied to Cattle. In cattle, the symptoms 

 of tuberculosis are not easily detected by methods of physical diag- 

 nosis until the disease has reached an advanced stage. In consequence, 

 cows may be elements of danger without appearing in any way diseased. 

 In consequence, routine examination of herds by the tuberculin test has 

 become one of the necessary measures of sanitation. According to 

 Mohler, 62 an accurate diagnosis may be established in at least 97 per 

 cent of the cases. It is natural that a good deal of objection to the 

 test is encountered on the part of dairy farmers and cattle raisers, and 

 it has been claimed that the cattle are injured by the test. There is, how- 

 ever, no scientific basis for this belief, if the test is carried out carefully and 

 intelligently. As a matter of fact, the systematic use of the test would 

 eventually be distinctly advantageous to the owners of the cattle them- 

 selves, since it has been shown that cows, even in the early stages of the 

 disease, may expel tubercle bacilli, either during respiration or with the 

 feces, and thus become a menace to healthy members of the herd. 



The tuberculin test on cattle should be made as follows: (The 

 directions given below are taken directly from the circular sent out. from 

 the Bureau of Animal Industry at Washington.) 



1. Begin to take the rectal temperature at 6 A.M., and take it very 

 two hours thereafter until midnight. 



2. Make the injection at midnight. 



3. Begin to take the temperature next morning at 6 A.M., and con- 

 tinue as on preceding day. 



To those who have large herds to examine, or are unable to give the 

 time required by the above directions, the following shortened course is 

 recommended: 



1. Begin to take the temperature at 8 A.M., and continue every 2 

 hours until 10 P.M, (omitting at 8 P.M., if more convenient) ; or take the 

 temperature at 8 A.M., 12 M., and 10 P.M. 



Mohler, Pub. H. and Mar. Hosp. Serv. Bull., 41, 1908. 



