TUBERCLE 73 



or so. Should there be no reaction, give c.c. (8| minims of 

 the solution as prepared) in a day or two's time, and if this 

 also causes no rise of temperature finish the test by giving 

 i c.c., or 17 minims, of the solution, containing ^o c.c. If 

 this causes no rise of temperature, the patient can be pro- 

 nounced non-tuberculous with some degree of certainty. The 

 test is of especial value in enabling us to prove the absence of 

 the disease rather than as a method of diagnosing its pre- 

 sence. Do not use tuberculin which has been diluted more 

 than a week. The test is obviously useless if the patient has 

 an irregular temperature to begin with. 



Tuberculin may also be used in children up to the age of 

 four or five years by von Pirquet's method. The skin (clean, 

 but not otherwise prepared) is g'ently scarified by means of a 

 glass pipette, lancet, or other suitable instrument, taking" care 

 not to draw blood. A drop of undiluted old tuberculin is 

 then applied, well rubbed in, and allowed to soak in without 

 being rubbed off; it is a good plan to cover the area with a 

 watch-glass or vaccination shield. The area is examined in 

 twenty-four and, if necessary, in forty-eight hours. In a nega- 

 tive case there is practically nothing to be seen. In a positive 

 one there is a flat-topped red papule after about twenty-four 

 hours; the redness may spread beyond the scarified area in 

 all directions, and vesicles may form on the papule. Unfor- 

 tunately, this test only indicates an existing or previous infec- 

 tion with tubercle, and the sensitiveness may last for years 

 after the lesion has been cured. For this reason it is of com- 

 paratively little value in adults, tubercle in one form or 

 another being so common in childhood. I think, however, 

 that a very marked reaction, even in an adult, usually indicates 

 a recent infection. 



Calmette's opthalmo-reaction may also be used, but is by 

 no means devoid of danger. 



Two additional methods of treating material for examination for 

 tubercle bacilli may be required occasionally. 



(i) Ellermann and Erlandsen's Method. Add to the sputum one- 

 half of its volume of a -6 per cent, sodium carbonate solution, shake 

 well, and incubate for twenty-four hours. Decant the superficial fluid, 



ntnfugahze the remainder, again pour off the supernatant fluid or 

 remove it with a pipette, add an excess (not less than four times 



