EXPERIMENT STATION BULLETINS. 517 



ing away of part or all of the diseased tissue. The tubercle bacilli were 

 not in the least injured by this change, and it was thought that in many 

 cases this broken down tuberculous tissue would be disseminated through- 

 out the body producing a generalized tuberculosis, in this way aggrava- 

 ting the condition very much. 



De Schweinitz and Dorset, from cultures of tubercle bacilli grown upon 

 a special cultural medium, have isolated a temperature reducing and a 

 temperature producing substance, the latter of which is much the same, 

 if not identical with tuberculin in raising the temperature, but much 

 more intense and effective. It is hoped that our crude tuberculin will 

 some day be simplified and made more reliable and constant. For if we 

 are to judge from the sentiments expressed by Babes and Proco of the 

 intimate relation of the germ-body to tuberculin, and of Koch in the prepa- 

 ration of his new tuberculin, we should be led to believe that this agent 

 has a future which has not yet been conceived and that the percentage 

 of error will still be lowered. The present indefiniteness of its component 

 action can only result in the determination of its perhaps several con- 

 stituents, one of which shall only be necessary for increased temperature 

 production in tuberculous subjects. 



HOW IS TUBERCULIN APPLIED ? 



In the treatment of this subject, we shall confine ourselves to its use 

 in the diagnosis of tuberculosis in cattle. 



The general principles underlying nearly all methods are: The ascer- 

 taining of the normal temperature; the injection of tuberculin; and, after 

 an interval of a few hours, the taking of temperatures during a period of 

 several hours. We can best gain a practical understanding by reviewing 

 the recommendations and work of others. 



The Bureau of Animal Industry at Washington, D. C, recommends the 

 following course in using their tuberculin: 



"1. Begin to take the rectal temperature at 6 a. m. and take every hour 

 thereafter until midnight. 



"2. Make the injection at midnight. 



"3. Begin to take the temperature next morning at 6 a. m. and continue 

 as on preceding day." 



To those who have large herds to examine, or who 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 two 

 hours until 10 p. m. (omitting at 8 p. m., if more convenient). 



"2. Make the injection at 10 p. m. 



"3. Take the temperature next morning at 6 or 8 a. m., and every two 

 hours thereafter until 6 or 8 p. m." 



The Pasteur Vaccine Co. of Chicago gives these directions in the use of 

 its tuberculin: "Before giving the injection, obtain the normal tempera- 

 ture. From the tenth to the twentieth hour after injection take the tem- 

 perature every two hours. [Strictly speaking, it is sufficient to take the 

 temperature only three times after injection, at the twelfth, fifteenth, and 

 eighteenth hours; but it is preferable to take the temperature every two 

 hours. ] 



