THE BEGINNINGS OF LIFE. 363 



an animal loses its powers whenever it becomes putrid ^. 

 This has been established by multitudes of experiments. 

 A drop of the diseased blood inserted beneath the skin 

 of rabbits was found to be always sufficient to reproduce 

 the disease; whilst a drop of ordinary blood, after it 

 had become putrefied and swarming with Bacteria^ 

 when similarly introduced, generally produced no effect. 

 Again, rabbits which had been fed upon the fresh 

 organs of some animals that had recently died of the 

 ^ blood/ almost invariably became affected by the same 

 disease, and soon showed myriads of the characteristic 

 organisms in their blood. Whilst of other animals which 

 were made to swallow similar quantities of liver, after 

 it had become quite fatid (and therefore swarming 

 with Bacterid)^ only one out of eight died; and even 

 that one, which was found to have suffered from an 

 inflamed lung, did not reveal any trace of organisms 

 in its blood. 



These experiments seem only explicable on the as- 

 sumption that, in the cases where the <^ blood' was 

 communicated to other animals by inoculation (either 

 subcutaneously or by the stomach), the disease was 

 communicated not so much by the direct multiplication 

 of the stock of inoculated organisms and their spread 

 throughout the body, as because some of the inoculated 



^ M. Davaine says : — ' Dans les grandes chaleurs de I'ete lorsque le 

 thermom^tre marquait de 28 a 32 degres centigrades, j'ai vu disparaitre 

 la faculte dont il s'agit en quarante ou cinquante lieures, ime fois en 

 trente-cinque heures.' (' Compt. Rend.' 1864.) 



