296 BACTERIOLOGY. 



moderate doses described, be considered absolutely 

 infallible. 



" No evidence in connection with the tuberculin test 

 as applied to man and animals has been forthcoming 

 thus far from those who have made use of it, which 

 would tend to sustain the general impression that this 

 method is necessarily dangerous and tends invariably 

 to aggravate the disease, and my own experience has 

 developed nothing which would seem to confirm this 

 impression. It is evident that the size of the doses 

 given has much to do with the limitations of this method 

 for usefulness and the correctness of the conclusions 

 reached by its application. The tuberculin used is also 

 a matter of some importance in determining the dosage, 

 as different samples vary considerably in their efficiency. 

 The minute amounts adopted by Grasset and Vedel 

 i. e., from 0.0002 to 0.0005 while they have the advan- 

 tage of absolute safety, may lead into error, as they 

 are insufficient, on the evidence of these observers them- 

 selves, to cause reaction in cases proven to be tuberculous 

 by the presence of the bacillus in the expectoration. If, 

 on the other hand, the test be pushed to the injection of 

 such large amounts as 10 mg. or more, as advocated by 

 Maragliano, such doses are by no means free from the 

 objection of occasionally causing unpleasant and some- 

 times dangerous symptoms; and even if the amount 

 given be not carried to the dose of 10 mg., which is 

 known to produce fever in healthy subjects, it is likely 

 that on account of individual susceptibility or the pres- 

 ence of some other morbid process in the body, reaction 

 will be found to occur with the larger doses when no 

 tuberculous process exists. The adoption of an initial 

 dose so small as to guard against the absolute possibility 



