332 IMMUNOLOGICAL METHODS OF DIAGNOSIS 



to those observed in the guinea-pig. The subcutaneous injection 

 of the non-tubercular individual with small doses of tuberculin will 

 thus produce no deleterious consequences whatever, while in the 

 tubercular subject the same dose causes the well-known general 

 response by headache, muscle pains, and fever, besides the local 

 inflammatory reaction at the site of the injection. In cases where 

 the tubercular lesion is superficially located and can be directly 

 observed the development of increased redness and swelling, more- 

 over, give evidence of a direct effect upon the seat of infection. 

 The same is shown by the increase in the number of the rales and 

 in the number of bacilli in the sputum, if the injection is given in 

 a case of pulmonary tuberculosis (focal reactions). 



If, on the other hand, the tuberculin is administered in such a 

 manner that active resorption does not occur, local reactions only 

 will be observed, and in tissues, it should be remembered, which 

 are not tubercular in themselves. Following a cutaneous inoculation 

 with tuberculin an inflammatory papule thus appears, no matter 

 at what point the injection is made (v. Pirquet reaction), instillation 

 into the conjunctival sac gives rise to an intense conjunctivitis 

 (Calmette reaction); inunction with a tubercular salve calls forth a 

 local dermatitis (Moro reaction), etc. 



Owing to this remarkable hypersusceptibility to tuberculin on 

 the part of the tubercular subject, the principle in question has been 

 extensively utilized for diagnostic purposes, and it may not be out 

 of place to describe briefly the most important methods which have 

 been advocated for this purpose. 



The Tuberculin Test According to Koch (Subcutaneous Method). 

 The material which is employed to this end is the old tuberculin of 

 Koch. Of this the patient receives from 0.1 to 1 milligram, accord- 

 ing to the condition of his general health. In feeble individuals 

 it is best to start with 0.1 milligram, while more robust persons 

 may take 1 milligram. The injections are conveniently given in 

 the back, below the angle of the scapula, and best during the early 

 forenoon hours. To wait until the evening is not advisable, as 

 the reaction may occur after six hours and might accordingly 

 be overlooked during the night. If no elevation of temperature 

 occurs after the first dose the quantity is doubled in forty-eight hours, 

 and so on until a dose of 10 milligrams, or in individuals of feeble 

 constitution, of 5 milligrams is reached. This Koch regards as the 



