486 THE TUBERCLE BACILLUS GROUP 
four or e^'en forty-eight hours. The temperature should })e taken at 
half-hourly intervals. There is frequently an initial chill following 
the introduction of tuberculin and in addition malaise, headache and 
restlessness; even nausea or vomiting may be observed. The focal 
reaction consists essentially of hyperemia and a distinct inflammatory 
reaction around active foci. In superficial foci, as in lupus, this 
inflammatory reaction may be distinctly seen, and in deeper foci 
it can be frequently demonstrated or at least inferred by an increase 
of local clinical signs. The local reaction at the site of inoculation 
consists essentially of a reddened, swollen, circumscribed area of 
inflammation. The specificity of the reaction is dependent upon the 
size of the dose of tuberculin. Too large a dose may cause a reaction 
even in a non-tuberculous subject. It is obvious that patients already 
exhibiting a febrile reaction due to intercurrent disease or otherwise 
are unfit subjects for injection, for the rise in temperature is the chief 
diagnostic symptom relied upon in establishing a diagnosis. 
The subcutaneous injection of old tuberculin is used only for adults 
and for children over five years of age in the very early stages of the 
disease. This reaction is claimed by some observers to be more deli- 
cate than any other tuberculin test. In practice tuberculin is intro- 
duced subcutaneously either in the breast or preferably in the back, 
and a control inoculation, using dilute glycerin containing 0.5 per 
cent carbolic acid, is made in another area. If a nodule and con- 
gestion appear at the site of inoculation of the tuberculin and the 
control area remains practically unchanged, the reaction is considered 
positive if the temperature chart taken at one-half-hour intervals 
shows at least one-half degree rise in temperature above that exhibited 
previously for several days. The size of the dose to be administered 
depends upon the age and condition of the patient and upon the 
potency of the old tuberculin. 
(b) The Cutaneous Test {von Pirquef).^— The patient's forearm is 
sterilized and 2 drops of undiluted old tuberculin are placed upon 
the skin about 8 to 10 cm. apart. A light scarification is made, pre- 
ferably with the von Pirquet scarifier, through each drop of tuberculin. 
A control scarification is made midway between the drops, but no 
tuberculin is applied here. A small pledget of cotton is placed over 
each drop of tuberculin and allowed to remain ten minutes to prevent 
the tuberculin from spreading beyond the site of scarification. The 
amount of cotton used should be small enough to prevent any con- 
siderable absorption of the tuberculin. No dressing is required. 
During the first few hours of vaccination the control and vaccinated 
areas appear the same, a slight area of inflammation due to trauma 
surrounding each. The specific reaction appears first as a slightly 
elevated red area around each drop of tuberculin, which increases in 
size and somewhat in elevation until it reaches a diameter of from 
1 Berl. klin. Wchnschr., 1907, 44, 644, 699. 
