208 PHARMACEUTICAL BACTERIOLOGY. 



upon the reactions produced by tuberculins when introduced into the 

 system: 



a. The Calmette or Ophthalmb Test, — Old tuberculin, precipitated by 

 alcohol is used. The precipitate is dried and made into a i per cent, solu- 

 tion in sterilized distilled water or sterile physiologic salt solution. This 

 substance is put up in sterile capillary pipettes, ready for use. A drop of 

 the solution is placed in one eye, using the other eye as a control. Any 

 abnormality in the eye is regarded as a contraindication, If tuberculosis 

 exists in the system it is indicated by an inflammation in the eye tested. 

 Also known as the Wolff-Eisner test or reaction. It may be necessary to 

 repeat the test several times before satisfactory results are obtained. 



b. Tht0von Pirquei or Cutaneous Test. — A 2S-per cent, solution of tuber- 

 culin (O. T.) is applied to the skin with scarification, as in vaccination. 

 The skin is first cleansed with alcohol and control scarifications are made 

 near the test area. This test is also known as the "skin reaction." It is 

 not very reliable. The inflammatory reaction may be simulated by other 

 substances in persons that are known to be entirely free from tuberculosis. 



c. The Moro, Percutaneous or Ointment Test. — Fifty per cent, tuberculin 

 (O. T.) in lanolin is rubbed into the skin, without scarification. The prep- 

 aration is put up in collapsible tubes, one tube containing enough material 

 for several tests. If tuberculosis exists, small reddened vesicles appear at 

 the point of inunction, usually on the second day. 



d. The Thermal Test. — A solution of tuberculin (O. T.), put up in 

 8 c.c. bottles, representing one milligram per c.c. (i-iooo) is injected hypo- 

 dermically. If tuberculosis is present there is a rise in temperature, usually 

 within ten to twenty-four hours after injection. 



e. The Detre Differential Test. — This test is intended to differentiate 

 between tuberculosis of human origin and that of bovine origin. Three 

 tuberculins are required. Tuberculin O. T., tuberculin B. F., made from 

 tubercle bacilli of human origin and tuberculin B. F., made from tubercle 

 bacilU of bovine origin. Three small skin areas are scarified. Into one 

 tuberculin O. T. is rubbed, into the second humanized tubercului, and into 

 the third bovinized tuberculin. The resulting reactions indicate whether 

 tuberculosis is of human or of bovine origin. 



We cannot go into the details of the reactions. They are not always 

 reliable, neither the positive nor the negative reactions. In the advanced 

 stages of tuberculosis and in moribund cases, the reaction is usually negative. 

 Indeed, in such cases the test is unnecessary as the existence of the disease 

 is evident without special tests. 



Tuberculosis is not as infectious as. is generally supposed. Those who 

 are in good condition physically may live for years with those afficted with 

 the disease without becoming infected. Yet, tubercular patients should be 



