SPECIFIC BACTERIAL REACTIONS 183 



cotton. At distances of about three inches, from above 

 downward, drops respectively of commercial " O T.," 

 human " B. F." and bovine " B. F." are expressed on 

 the skin from capillary tubes. In the medium of each 

 drop the underlying skin is scarified, care being taken 

 to cleanse the scarifier in passing from one variety of 

 tuberculin to the other. The inoculated sites should 

 be inspected every twelve to twenty-four hours. If no 

 reaction takes place in three days the test may be pro- 

 nounced negative. Positive reactions differ in no re- 

 spect from those described under the von Pirquet test. 

 Detre points out that a greater reaction at the site of 

 inoculation with the bovine tuberculin means tuber- 

 culosis of that type and indicates the use of tuber- 

 culin of the bovine type in therapy ; also that if greater 

 reactions occur with the Denys filtrates than with 

 *' O. T.," Koch's old tuberculin should be employed 

 in immunization and vice versa. Marked reactions are 

 usually observed in early virulent infections, although 

 not infrequently they occur in the chronic latent form 

 of the disease, including surgical cases. The reaction 

 to filtrate is prone to disappear more in old chronic 

 cases. Routine periodic applications of the test are 

 necessary if it is to be utilized as a control of therapy. 

 Method of Percutaneous Anointment. — Moro de- 

 scribes the use of an ointment compounded of equal 

 parts of tuberculin " O. T." and refined anhydrous 



