BACILLUS TUBERCULOSIS. 131 



The close should not give rise to a temperature exceeding 

 1 C. 



This produces very satisfactory results in the treatment 

 of lupus, but so far in tuberculous diseases of the lung its 

 eifects have not come up to expectation. 



Bazillen Emulsion. This bacillary emulsion is a later product 

 of Koch, and is really a combination of T. O. and T. R. Each 

 c.c. contains 5 mg. of solid substance. 



Deny's bouillon filtrate corresponds to Koch's O. T., but is 

 not heated in its preparation, and is supposed to contain some 

 thermolabile substances, which, in the case of O. T., are sup- 

 posed to have been destroyed by the heat. All of these tuber- 

 culin preparations have been used in the hope of promoting an 

 active immunity in cases of tuberculosis. In later years greater 

 care in their administration and the avoidance of large u reac- 

 tion " producing doses have conduced to better results. 



Old tuberculin has been considerably used in recent years as 

 a diagnostic agent, y 1 ^ of a milligram in 0.5 per cent, carbolic 

 acid solution being injected siibcutaneously. In positive cases 

 this injection is followed in six to eight hours by a marked 

 rise of temperature. This subcutaneous method has been 

 found not to be without danger, and is little used now. 



The ophthalmic reaction of Calmette, obtained by instilling 

 into the conjunctival sac a J to 1 per cent, solution of O. T. in 

 normal salt solution. (The O. T. must before dissolving be 

 heated with 95 per cent, alcohol and dried in vacuo over sul- 

 phuric acid.) One drop of this solution is nsed in one of the 

 eyes, and a positive reaction is indicated by a congestion and 

 inflammation of the conjunctiva, sometimes violent in nature. 

 Reports of permanent bad results in a goodly number of cases 

 have helped to bring this method of diagnosis into disfavor. 



The von Pirquet skin reaction, from a standpoint of accuracy 

 and safety, is probably the most available of the tuberculin 

 diagnostic methods. Originally von Pirquet used a 25 per 

 cent, solution, but later pure O. T. was substituted. A single 

 drop is placed on the sterilized skin of the arm and scarifica- 

 tion is done through it. A positive result is indicated by a 

 local reaction and elevation of temperature. 



Moro's ointment, by means of which a local reaction is ob- 



