LTJETIN REACTION 601 



One advantage of this test is that the animal will give a reaction in 

 cases where, prior to the test, dishonest dealers have injected tuberculin. 



The Cutaneous Tuberculin Test. In making this test some con- 

 venient area is shaved and scraped slightly until serum exudes. A small 

 amount of Koch's old tuberculin is applied to the prepared area. In a 

 positive case a well-marked area of congestion and hyperemia appear 

 at the end of twenty-four hours. This may also be accompanied by a 

 rise in temperature. 



The Intracutaneous Tuberculin Test. In performing this test 

 from 0.2 to 0.4 c.c. of Koch's concentrated tuberculin are injected into 

 the skin through a fine needle. A white swelling should appear while 

 the injection is being given; if it does not appear, the injection is sub- 

 cutaneous and unsatisfactory for this test. The appearance of hyper- 

 emia and redness with a rise in temperature indicates a positive reaction. 



LUETIN REACTION 



The clinical course of syphilis indicates that the infecting micro- 

 parasite, Treponema pallida, possesses all the qualities essential to the 

 development of an anaphylactic condition in syphilitic patients. Thus 

 the primary lesion appears after an incubation period of two or three 

 weeks. The secondary stage is manifested by periodic waves of various 

 general symptoms; the primary, secondary, and tertiary lesions show 

 a qualitative difference. Stimulated by von Pirquet's discovery of a 

 specific cutaneous reaction for tuberculosis, a number of investigators 

 (Finger and Landsteiner, Wolff-Eisner, Nobe, Ciuffo, Nicolas, Favre, 

 and Gauthier) attempted to obtain a specific reaction for syphilis by 

 applying extracts of syphilitic tissues prepared from syphilitic fetal 

 liver or chancre to the skin of syphilitic patients. In spite of some 

 encouraging effects their results were, on the whole, contradictory. 

 Further, Neisser and Bruck found that a reaction similar to that pro- 

 duced with syphilitic extract can be obtained also with a concentrated 

 extract of norrnal liver. This peculiarity of the skin of syphilitics is 

 ascribed by Neisser to what he calls the state of " Umstimmung" in the 

 later stages of syphilis. Both Neisser and von Pirquet expressed the 

 hope and belief that a reaction may be secured by employing an extract 

 of pallida free from tissue constituents; this was first and finally ac- 

 complished by Noguchi, 1 in 1911, first with syphilitic rabbits and then 

 with human patients. Noguchi gave the appropriate name of "luetin" 

 1 Jour. Exper. Med., 1911, 14, 557; Jour. Amer. Med. Assoc., Iviii, 1163. 



