46 I'he Philippine Journal of Science i9i7 



gall bladder by means of a syringe. A sample of blood was also 

 taken from the ear vein. The bile was of a light yellowish color 

 and contained a large amount of mucus. No blood was found 

 upon microscopical examination of the contents of the gall blad- 

 der. Centrifuged, it became clear and was subjected to the agglu- 

 tination test. The serum showed positive agglutination in all 

 dilutions up to %2oo- The contents of the gall bladder gave posi- 

 tive agglutination in dilutions %o ^.nd %o- Since the results of 

 this experiment as well as those of the preceding tests are in 

 accord with the results arrived at by Viole in his studies on this 

 particular question, it was thought unnecessary to extend our 

 experiments any further. The most important facts bearing on 

 the question of experimental cholera carriers, namely, the pres- 

 ence of immune bodies in the blood of experimental cholera car- 

 riers and their occurrence in the content of infected gall bladder 

 in immunized animals, has been demonstrated. Considering the 

 findings of Viole and our own, one is inclined to expect that 

 vaccination should exert some influence upon the state of cholera 

 carriers in experimental animals. 



In order to decide this important question, the following experi- 

 ments were arranged : 



II. PREVENTIVE VACCINATION AND EXPERIMENTAL CHOLERA 



CARRIERS 



A series of guinea pigs was immunized by injecting a suspen- 

 sion of cholera vibrios in physiological salt solution heated at 60° 

 C. for thirty minutes. These injections were given either under 

 the skin or intraperitoneally. At intervals of time, given in 

 Table III, the vaccinated animals were infected with live cholera 

 culture by intra vesicular injection. One tenth of a slant of live 

 cholera culture was injected. A series of normal animals, that 

 is to say guinea pigs that had received no preventive treatment, 

 was infected simultaneously and in the same manner as the 

 immunized ones. At intervals varying from one to thirteen 

 days after the intravesicular infection the animals were killed 

 and the various sections of the digestive system were examined 

 for the presence of cholera vibrios. The thirteenth day was taken 

 as the upper limit of time, since it became known in previous 

 experiments (3) that after the fourteenth day some of the ex- 

 perimental carriers became spontaneously negative. 



