﻿240 STRONG. 



positive result obtained. The blood serum was collected from one to four months 

 after the beginning of the illness. 



Uriate 5 " in a study of epidemics of pest in Paraguay, Rosario and Buenos 

 Ayres, found that the sero-agglutination of the pest organism occurred in cases 

 of plague only late in the course of the disease and then very irregularly. It 

 failed actually in more than 300 cases which, from a bacteriological and clinical 

 standpoint, were certainly those of pest. 



On the other hand Paltauf, 57 Markl " ,s and Kolle and Martini 50 showed that 

 a specific agglutination of the organism occurred in various dilutions with pest 

 immune sera produced in horses and other animals by repeated injections of the 

 plague bacillus. Paltauf found that in horses immunized by repeated inoculations 

 a reaction occurred in dilutions of 1 to 20. A distinct agglutination occurred 

 within one hour in dilutions of 1 to 100 with the sera with which Markl worked. 

 Kolle and Martini with less virulent cultures of the pest bacillus obtained a 

 reaction within one hour in dilutions of 1 to 1,000 to 1 to G.000. Kolle and 

 Otto 1!CI in the study of two pest immune sera found that agglutination occurred 

 within fifteen minutes in as high dilutions as 1 to 400. Klein 01 also reported 

 that the blood of vaccinated guinea pigs showed an agglutinative value in dilu- 

 tions of 1 to 20 or 1 to 30, the reaction occurring in fifteen minutes. 



The German Plague Commission and Kossel and Overbeck °~ emphasized the 

 difficulty or impossibility of securing a suspension of the freshly grown pest 

 bacillus which microscopically was free from clumps of the organism, and there- 

 fore they recommended that the test should be made macroscopically in the test 

 tube and the reaction observed with the assistance of a hand lens. The time 

 recommended for the observation of the test was from one-half to one hour, the 

 suspension being placed in the incubator at 37° C. for this period. However, Kolle 

 and Martini recommended that the reaction be noted after five minutes, since 

 in their experience spontaneous precipitation of the bacteria sometimes occurred 

 after one hour. 



Klein C3 pointed out that cultures of the pest bacilhis on agar possess a sticky, 

 viscid growth due to the production of a gelatinous interstitial substance which 

 is insoluble in bouillon. He therefore recommended physiological salt solution 

 as a medium for preparing the suspension. He also found that the addition of 

 bouillon to a saline suspension of the pest organism caused clumping of the 

 bacteria. 



Gauthier and Raybaud M found that precipitation of the bacteria also frequently 

 occurred with plague cultures grown on gelatine and suspended in saline solution 

 and that after two hours a spontaneous, flocculent sedimentation which resembled 

 true agglutination was apt to form. 



In my studies of the agglutination of the pest bacillus, I have fre- 

 quently found the same difficulty in securing complete suspensions of 

 the organisms owing to their sticky, viscid growth, even when saline 



56 Mitt. a. d. sektion f. Hyg. d. Kongress des Ass. francaise pour Pavancement 

 des sci. tenu Grenoble 1904, Arch. f. Schiffs v. Trop. Egg. (1005). 9, 80. 

 "Wien. Klin. ^Yclvnscll. (1897), 10, 537. 

 ™Centrbl. f. Bakteriol. (1901). 29, 810. 



59 Deutsche med. 'Wchnsch. (1902), 28, 46. 



60 Ztschr. f. Hyg. u. Infectionskrankh. Leipz. (1902), 40, 595. 

 61 Arl). a. d. I: Gsndhtsamte, Berl. (1902), 18, 114. 



03 Lancet (1901), 1, 450, 1535. 



e3 Ibid. 



M Oompt. raid. .S'oc. de biol., Par. (1904), 56, 391. 



