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shaved abdomen. Other animals should receive subcutaneous and 

 intraperitioneal inoculations of the suspected material triturated 

 with sterile phj^siologic salt solution. 



(8) After twenty-four hours the tube and plate cultures are 

 to be examined with the naked eye^ with the aid of the magnifying 

 glass and in stained cover-glass preparations. The animals like- 

 wise are to be examined. Some of those which have received 

 intraperitoneal injections are liable to succumb to the plague infec- 

 tion after twenty-four hours. 



Martini has worked out a special method in the examination of guinea 

 pigs infected cutaneously. Since this method often enables us to make a 

 definite diagnosis in doubtful plague cases after forty-eight hours, it is 

 to be recommended. His method is as follows: 



(a) The material suspected of containing the plague bacilli is triturated 

 with about three times the quantum of sterile bouillon. This emulsion 

 is rubbed with the back of a knife on the shaved abdomen of several 

 (five or six) guinea pigs. 



(b) After twenty-four hours the guinea pigs are examined for swollen 

 lymph glands, and if any are found, their juice is drawn with a sterile 

 syringe and inoculated into agar tubes, and also examined in smears. 



(c) If what appear to be plague bacilli are found in the smears, two 

 rats are inoculated intraperitoneally with tlie juice obtained from the 

 enlarged gland of the guinea pigs. 



(d) The cultures obtained from the juice are examined macroscopically 

 and microscopically and tested with an antiplague serum of known 

 agglutinating power. 



The agglutination test can not be made, it should here be stated expressly, 

 with antiplague sera selected "at random," because some have little 

 or no agglutinating power, as has been repeatedly pointed out by several 

 observers, including the Indian Plague Commission. (Vol. V, p. 68 of 

 report. ) 



Kolle and Martini recommend the desiccated antiplague serum of the 

 Pasteur Institute for the agglutination test. The dry fine powder is 

 first dissolved in ten times its weight of sterile distilled water (I gram 

 to 10 cubic centimeters. The solution is complete after several hours, 

 whereupon the further dilutions necessary for tlie tests can be prepared. It 

 is found that this dry serum will agglutinate genuine plague cultures, and 

 only those, in dilutions of from 1:1,000 to 1:6,000. The less virulent the 

 plague culture the greater the agglutinating powder of the dry serum; 

 and vice versa, the more virulent the cultures, the lesser the agglutinating 

 power. 



Zlatogorofi", who studied the question as to how long plague bacilli 

 remain alive and virulent in cadavers under various conditions of tem- 

 perature and moisture, maintains that the cutaneous method of Golm 

 and Albrecht for infecting guinea pigs, is absolutely reliable only as long 

 as the organs do not contain any considerable number of putrefactive and 



