THE TUBERCLE BACILLUS 497 



and others and the new therapy fell into almost complete neglect. At 

 present, the use of tuberculin has again been revived, but with greater 

 caution and with a thorough understanding of its limitations. The 

 tendency has been toward smaller dosage and the limitation of the agent 

 to early cases. No two institutions use tuberculin in exactly the same 

 manner, and it is, therefore, impossible to do more than outline the 

 general scheme of treatment. It must never be forgotten, however, 

 that all forms of tuberculin treatment consist in an "active immuniza- 

 tion" in which, for the time being, the toxemia of the patient is increased 

 rather than neutralized. It is obvious, therefore, that only such cases 

 are at all suitable for treatment in which the process is not a very acute 

 one. The general principle of modern tuberculin therapy seems to lie 

 in choosing doses so small that no marked general reaction shall follow. 

 The preparations most frequently employed are Koch's "Alttuber- 

 culin," his "TR," his "Neu Tuberkulin-Bazillen Emulsion," and the 

 Bouillon filtre of Denys. Initial doses of Alttuberculin range from 0.1 

 to 0.01 of a milligram. In case of successful avoidance of a reaction, 

 the injection may be repeated, gradually increasing, about twice a week. 

 The occurrence of a reaction should be the signal for a longer interval 

 and a slower advance in the size of the dose. 



The initial dose of "TR" is, as advised by Koch, 1 about 0.002 

 mgm. This usually causes no reaction. The dose is doubled, at reason- 

 able intervals, up to 1 mgm. After this, further increase is care- 

 fully gauged by the clinical indications. The maximum dose is about 

 20 mgm. 



"Neu Tuberkulin-Bazillen 'Emulsion," 2 is begun with a dose of 0.001 

 mgm. Gradual increase as with the other preparations is then prac- 

 ticed. The maximum dose is about 10 mgm. 



Bouillon filtre has been used chiefly by Denys 3 and with apparently 

 excellent results. Denys is very emphatic in advising the absolute 

 avoidance of any reaction. He begins with a millionth or even the 

 tenth of a millionth of a cubic centimeter of the bouillon and in- 

 creases with extreme caution. His dilutions are made with glycerin 

 broth. 



Passive Immunization in Tuberculosis. Numerous attempts have 

 been made to immunize tuberculous subjects with the sera of actively 



1 Koch, Deut. med. Woch., xiv, 1897. 



*Bandelier und Roepke, "Lehrb. d. spezifisch. Tub. Ther.," -Wur/burg, 1908; 

 Koch, Deut. med. Woch., 1901. 



3 Denys, "Le Bouillon filtre," Louvain, 1905. 



