THE MANUFACTURE OF ANTISERA. 487 



of Von Pirquet* depends upon the cutaneous application of the tuberculin. 

 One drop of tuberculin (old) is placed on the arm, after cleansing the 

 skin, and the small area under the drop is scarified. Two or more small 

 areas may be treated in this way, as well as a control area treated with 

 sterile salt solution or a solution of glycerin and dilute carbolic acid in 

 substitution for the tuberculin. The appearance of a reddish zone in 

 from twelve to twenty-four hours indicates a positive reaction. This 

 area of inflammation gradually increases somewhat in elevation and 

 diameter and finally subsides in a few days. Moro'sf modification 

 of von Pirquet's method consists in the use of tuberculin ointment pre- 

 pared by the combination of tuberculin (old) and anhydrous lanolin 

 in equal parts. The ointment is vigorously rubbed on a small portion 

 of the skin of the abdomen. A positive reaction is evidenced by the 

 appearance of a distinct granular or papular eruption at the point of 

 application after about twenty-four hours. 



Tuberculin (old) is usually distributed in small vials, sealed and 

 labeled. The labels should indicate the amount and dosage and the 

 date of preparation. Under the influence of light and heat the fluid 

 product may slowly deteriorate, therefore, when possible, it should be 

 kept in the refrigerator until needed. 



OTHER TUBERCULINS. Koch introduced tuberculin "T. R." (tuber- 

 culin residuum) in 1897 and tuberculin "B. E." (bacillary emulsion) 

 in 1901. The former is prepared by repeatedly centrifugalizing a 

 suspension in water of the dried and ground tubercle organisms. The 

 supernatant fluid "T. O." after the first centrifugalization is discarded 

 and the final product consists of the constituents of the bacteria which 

 are insoluble in water, i c.c. of the tuberculin "T. R." should contain 

 the equivalent of i mg. of the dry tubercle solids. Tuberculin B. E. is 

 composed of a suspension of crushed or thoroughly ground tubercle 

 organisms in 50 per cent glycerin solution. Each cubic centimeter should 

 contain the equivalent of i mg. of tubercle solids. Tuberculin T. R. and 

 tuberculin B. E. are used as therapeutic agents, the latter probably being 

 regarded with more favor by clinicians. The material is administered 

 by subcutaneous injection, the time intervening between successive 

 treatments varying from three to ten days. The initial dose recom- 

 mended by Wright is .04 mg. to .006 mg.; certain other workers em- 

 ploy much smaller doses, .0001 mg. or less. 



* Von Pirquet: Berl. Klin. Wchnschr., 1907, 44. 

 t Moro: Munch. Med. Wchschr., 1908. 



