﻿40 The Philippine Journal of Science im 



The next step was to locate, if possible, the blood element 

 which harbored the virus. For assistance in this work, I am 

 greatly indebted to Dr. M. A, Barber of the Bureau of Science. 

 Doctor Barber used his pipette method for the isolation of single 

 microorganisms to pick out and separate the different blood 

 elements. 



Two susceptible animals received, respectively, 200 and 255 

 red blood cells from an animal sick with rinderpest. The 

 animals were unaffected by the injections, and at a later date 

 they were proved to be susceptible. Two animals were injected 

 with 15 and 40 leucocytes, respectively, obtained from the blood 

 of infected animals. They were unaffected by the injections, 

 but later were proved to be susceptible. Three anirhals were 

 injected with blood platelets. They received, respectively, 

 6,000, 770, and a large number, the exact count not determined. 

 These animals remained well, but later were proved to be sus- 

 ceptible. The blood from which these elements were taken was 

 checked in each case and found to be virulent. 



The question then arose, does the virus occur as thickly dis- 

 tributed in the blood of an infected animal as was previously 

 supposed. Therefore, it became necessary to determine the 

 smallest dose of whole blood that would cause the disease. Fine 

 capillary pipettes were made, and a certain length was marked 

 on the glass. The weight of mercury filling this designated 

 portion was compared with the weight of 1 cubic centimeter 

 of mercury. In this way the capacity of the minute quantity 

 defined by the mark on the capillary tube was approximately 

 obtained. It was found that ^970 cubic centimeter of virulent 

 blood transmitted the disease to a susceptible animal, but %o6o 

 cubic centimeter and 0.0001 cubic centimeter of virulent blood 

 failed to transmit the disease. The susceptibility of these ani- 

 mals was proved later. These results gave an approximate 

 indication of the minimum amount of virulent blood which would 

 transmit the disease and were an aid in the culture work for 

 comparison with the dilution of the original blood brought about 

 by successive transfers in culture media. 



The final step was to find a medium in which the virus would 

 remain alive and multiply. Many unsuccessful attempts were 

 made using various kinds of media. The virus would either die 

 or at least lose its virulence in from thirty-six to sixty-eight 

 hours. -In no case was the second tube of medium shown to 

 contain virus. Finally, apparently positive results were obtained 

 by modifying slightly the medium described by Nencki, Sieber, 



