1883.] On the Jnfectivity of the Blood and other Fluids. 465 



the strongly fetid odonr caused by the development of the vegetation 

 was remarkable and distinctive, and was observed in the case of every 

 tube opened, both those with serum and those with bouillon. Their cul- 

 tivation was repeated four times, in exactly similar manner, each cul- 

 tivation lasting two or three days, and precisely similar appearances 

 being observed in each. From the fifth collection, which contained 

 the Bacillus in considerable numbers, five drops, diluted with an equal 

 quantity of normal saline solution, were injected into the subcutaneous 

 tissue of the abdomen of guinea-pig A, which died with the usual, 

 though slight, symptoms of infection in about forty hours after 

 inoculation. Another guinea-pig, B, at the same time received in 

 like manner ten drops of the same fluid, diluted 1,000 times 

 ( = T i-Q gtt. of the cultivation). This animal was perfectly un- 

 affected, beyond a slight local and temporary irritation at the spot of 

 injection, which, without infection, sometimes occurs with animals 

 inoculated in the abdomen, and arises probably, as I have witnessed, 

 from their scratching ; it passed off within forty-eight hours and the 

 animal remained unaffected. The quantity of fluid here injected 

 must have contained many thousands at the least, and probably some 

 millions of the Bacilli, bub they do not appear capable per se of 

 developing to any extent in the tissues of a healthy animal. 



From these experiments I conclude that in the affections here in 

 question, that is, in Davaine's septichasmia in the rabbit and the so- 

 termed Pasteur's septicha3mia in the guinea-pig, there is no increase 

 of infective virulence in the septic fluids in successive generations, 

 either in respect to the minimal quantities required to produce fatal 

 infection, nor as to any constant difference in the incubation period, 

 though in the latter case this period is less constant than obtains in 

 Davaine's septichaemia ; the infectivity, too, of the inflammatory pro- 

 duct, though not comparable in virulence to septichasmic blood, is 

 here more variable, partly owing it may be, as Dr. Sanderson 

 originally considered, to differences in the severity of the cases afford- 

 ing the infective matter, and partly also, as I have above stated, to 

 constitutional idiosyncrasy in the animal inoculated. 



With respect to the nature of the contagium and the relation of the 

 micro-organism to the disease in which they occur, I conclude that in 

 the first case, i.e., in Davaine's septichaemia in the rabbit, all the 

 circumstances taken into consideration, the microphyte constitutes the 

 actual contagium, and that the numbers in which it is present in the 

 blood, both septic (putrid) and septichasmic, clearly condition its 

 infective virulence. Its numbers alone would not account for the 

 difference in the incubation period — so-called — of the two cases, but 

 the purity of the growth in the latter case, and in the other the fact 



