VACCINE TREATMENT OF TUBERCULOSIS 209 



people are to be injected at one time it is better to use the smaller size. 

 From this four dilutions are prepared by starting with a 1 in 10 (A) 

 of the original strength, by then making a 1 in 10 from this (B); 

 a 1 in 10 from that (C), and a 1 in 10 from the last (D), using sterile 

 water as diluent, and working with sterile glassware. As 1 c.c. of 

 the original product represents 1000 milligrams of the pure tuber- 

 culin, 1 c.c. of dilution A will contain 100 milligrams, 1 c.c. of B 

 10 milligrams, 1 c.c. of C 1 milligram, and 1 c.c. of D 0.1 milligram; 

 from which latter further dilutions can be prepared according to the 

 same plan, as desired. 



As initial dose, that amount is suggested which a preliminary 

 diagnostic examination has shown to produce a systemic reaction 

 (see Tuberculin Test) . If this is for any reason omitted, it is best to 

 start the patient with 0.1 milligram, and to increase the dose progres- 

 sively at intervals which are determined according to the activity 

 of the reaction, and which accordingly vary from one to two weeks. 

 In the event of a marked reaction, it is best to repeat the last dose, 

 or to increase this only very slightly. A reversion to a smaller 

 dose is to be avoided, and it is better, if need be, to wait a week 

 longer before the next injection is given. In the light cases it is thus 

 possible to run up to a dose of 1000 milligrams without much trouble, 

 while in the presence of more advanced lesions this is more difficult; 

 when the higher doses are reached the intervals between the injec- 

 tions may have to be lengthened to a month or even longer. The 

 treatment is virtually considered at an end when the patient 

 can stand a dose of 500 milligrams without marked systemic 

 reaction. 



New Tuberculin. 1 c.c. of new tuberculin represents 5 milli- 

 grams of the dry powder. Koch recommends that the injections 

 be started with a dose of 0.0025 milligram. To this end the original 

 product is diluted with sterile water to the required degree, so that 

 the amount to be injected is less than 1 c.c. in bulk, as larger quan- 

 tities favor the development of local infiltration. For convenience' 

 sake we can start with a dilution of the original product of 1 in 10 

 (A), 1 c.c. of which in turn is diluted 1 : 10 (B), and of this again 1 c.c. 

 in the same proportion (C) ; 1 c.c. of A then contains 0.5 milligram, 

 1 c.c. of B 0.05, and 1 c.c. of C 0.005; 0.5 c.c. of the latter dilution 

 being thus the initial dose. 



The injections are at first given four days a part, and later when 

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