650 ANAPHYLAXIS IN RELATION TO INFECTION AND IMMUNITY 



dissolving in water so that from one-third to one-half milligram is 

 contained in each drop. In typhoid-fever patients reaction of the 

 palpebral conjunctiva of the lower lid and of the caruncle appears on 

 an average of two and a half hours later, reaching the maximum about 

 the sixth hour, and usually subsiding within forty-eight hours. In 75 

 cases of typhoid fever this test was found positive in 71 and negative 

 in four. In three cases the eye test antedated the Widal reaction, and 

 in only 23 per cent, was the Widal reaction positive at as early a date 

 as the eye test. A study of 190 persons normal or ill with diseases 

 other than typhoid has convinced Austrian of the specificity of the test, 

 and he recommends it as an aid to diagnosis on account of its simplicity 

 and the absence of any discomfort to the patient. 



More recently, Gay and Force 1 have reported favorably upon a 

 cutaneous reaction indicative of immunity against typhoid fever. The 

 preparation which they used, "typhoidin," is prepared in the same man- 

 ner as Koch's old tuberculin: 250 c.c. of a 5 per cent, glycerin bouillon 

 is inoculated with Bacillus typhosus and cultivated at 37 C. for five 

 days. It is then reduced, without filtration, to one-tenth of its original 

 volume by evaporation over an acetone bath for about eight hours. 

 A control solution of sterile 5 per cent, glycerin bouillon is prepared in 

 the same manner. 



The skin of the forearm is cleansed with alcohol, and two abrasions 

 are made with the von Pirquet borer, as described under the cutaneous 

 tuberculin test. The "typhoidin" is applied to one cut and the control 

 fluid to the other. The reactions are observed six and twenty-four 

 hours later. Occasionally there is a traumatic reaction in the control, 

 but a positive reaction may be detected by a wider areola and increased 

 induration. 



Positive reactions were secured in 95 per cent, of cases that had re- 

 covered from typhoid fever, two of the cases having had the disease 

 respectively forty-one and thirty-three years before. The reaction was 

 found negative in 85 per cent, of individuals not having typhoid fever. 

 Of 15 persons immunized by the army method, from four and three- 

 quarter years to eight months previously, nine gave a positive skin 

 reaction. Twenty-four individuals immunized by a sensitized vaccine 

 (Gay and Claypoole) for from one to eight months previously reacted 

 positively. Later Gay and Claypoole 2 prepared typhoidin by precipi- 

 tating the solution with alcohol, washing the precipitate with alcohol 



1 Archiv. Int. Med., 1914, 13, 471. 



2 Archiv. Int. Med., 1914, 14, 671. 



