vii INFECTION OF ANIMALS WITH PLAGUE 185 



Guinea-pig No. 2 developed a bubo slowly ; it was 

 found dead on July 11. Post-mortem examination 

 showed typical subacute plague. 



Experiment 2. — Guinea-pig No. 3 was injected (on 

 July 4) with " sand -gelatine," dried for three days. 

 Guinea-pig No. 4 was injected on July 5 with " earth- 

 gelatine/' dried for three days. 



Guinea-pig No. 3 developed bubo slowly ; this became 

 a big abscess by July 13. The same condition was 

 observed with guinea-pig No. 4. But both animals 

 appeared otherwise lively. Both were killed, and on 

 post-mortem examination the pus of the buboes was 

 found to contain, amongst cocci, crowds of B. pestis. 

 The viscera appeared unaffected. 



Experiment 3. — Both the dishes containing "sand- 

 gelatine " and " earth-gelatine " were removed from over 

 the sulphuric acid after lapse of three days and were then 

 kept under simple glass cover (raised about half an inch 

 at one side) at the temperature of the laboratory. 



Six days after withdrawal from the influence of the 

 sulphuric acid, the " sand-gelatine " was used for sub- 

 cutaneous injection (on July 9) of guinea - pig No. 5 ; 

 and five days after withdrawal the " earth -gelatine" was 

 used in similar manner for injection (on July 9) of 

 guinea-pig No. 6. 



Guinea-pig No. 5 was on July 15 without tumour 

 and quite lively ; and it remained so. Guinea-pig No. 6 

 died on this day (July 15). On post-mortem examina- 

 tion there was evidence of typical subacute plague : big 

 necrotic bubo with crowds of plague bacilli, liver and 

 spleen permeated with minute white nodules containing 

 numerous B. pestis. 



