1883.] On the Infectivity of the Blood and other Fluids. 467 



and Feltz, but imperfectly as above mentioned, and this, as far as I 

 know, is the only attempt to describe them at all particularly ; the 

 terms in which the microphytes they mention are referred to by 

 later French writers are most vague, while others have scarcely alluded 

 to their presence, save in the most general manner, while recording 

 experiments made with the object of investigating the aetiology of 

 these diseases. 



In the case of Davaine's septicheemia, I have been able in all 

 essential points, not only to confirm his original statements, but to 

 account for them, more especially with regard to the incredibly minute 

 quantities in which the blood in these cases is infective, statements 

 the accuracy of which has been sometimes doubted. To emphasise 

 this is due to the reputation of one who has done so much in many 

 directions to advance our knowledge of micro-parasitical diseases, and 

 indeed, it may be said that almost the only points left undetermined 

 by this observer, or the mistakes which he made,* were those depen- 

 dent upon microscopical investigations, the immense advance in the 

 appliances of which the last few years now enables this to be done. 

 In the other case, the so-termed Pasteur's septichaBmia in the guinea- 

 pig, the relations of the Bacillus therein occurring are not so clearly 

 shown as in the former, yet if its characters of morphology and 

 mobility as above mentioned had been carefully observed, neither 

 this affection, nor, still less, the former, could for an instant have been 

 confounded with charbon or anthrax, as was the case ; nor again in 

 this latter disease could any observer have fallen into the grave error 

 of confounding the B. anthracis with either the Bacillus here in 

 question, or the hay Bacillus, the characters above briefly described 

 being perfectly constant and sufficiently distinctive to be at once 

 readily recognised under even moderate magnifying power. 



It is on the microscope that I have relied for determining the 

 questions herein, and it appears to me that it is on the more assiduous 

 use of its greatly increased powers which we now possess, that the 

 advancement of our knowledge of these subjects depends. 



The observations here recorded were commenced and chiefly per- 

 formed in the Physiological Laboratory of the New Museums at 

 Cambridge, during the last winter (1881) : circumstances have delayed 

 their final completion till lately, in the meantime an article on the 

 same subject has been published at Berlin, by one of Dr. Koch's 

 assistants, Dr. Gr. Ga:ffky,t who has arrived at the same conclusions 

 mainly as myself with reference to the principal point in question ; but 



* As in regarding the specific organism of septichaemia and the putrid ferment as 

 one and the same. 



f " Experimentell erzeugte Septikamie, &c," in " Mittheil. a. d. Kaiserl. Gresund- 

 heitsamte, &c," Berlin, 1881. 



