450 



Mr. G. F. Dowdeswell. 



[Jan. 18, 



reproducing in other animals those symptoms which have occurred 

 in it, though previously asserted by others, was first conclusively 

 demonstrated in 1866 by MM. Coze and Feltz in France,* who 

 further stated that in successive inoculations from one animal to 

 another of the same species, such blood acquires a progressive increase 

 of virulence', becoming more toxical than putrid matter itself, and 

 that death follows inoculation with increasing rapidity. These 

 observations were confirmed and greatly extended by Davaine, f in 

 long investigations ; hence the form of septichsemia here in question 

 has since been known by the name of the latter observer. The first- 

 mentioned writers founded their assertion of an increase of infective 

 virulence upon the alleged fact that in successive inoculations^ the 

 incubation period was progressively shortened; whereas Davaine sought 

 to show, by numerous experiments, that in the same manner succes- 

 sively smaller quantities of blood were required to create infection ; 

 that whereas to originate it some drops were necessary, ultimately, 

 after several generations of transmitted infection, the billionth (in the 

 French notation the trillionth) part of a drop, or less, was sufficient ; 

 but he regarded, indeed defines, septichsemia as a putrefaction of the 

 blood in the living animal, a view naturally encouraged by the decom- 

 position which in these cases occurs so rapidly after death. 



Davaine's experiments were repeated by many observers, both in 

 France and elsewhere. § It is remarkable, however, that they one and 

 all contented themselves with merely reproducing his earlier obser- 

 vations, inoculating in succession several animals with constantly 

 diminishing quantities of blood, but without making any control expe- 

 riments to ascertain whether in the first stages the blood was not 

 already infective in the degree supposed to be attained only after 

 several generations, and overlooked the fact that, in his later writings || 

 Davaine had qualified his first statements by showing that a maximum 

 of infectivity was attained in the earlier generations. These conclu- 

 sions and the theory of an increase of infective virulence in successive 

 inoculations have since been generally accepted ; but the question here 



* " Recherches Cliniques et Experimentales sur les Maladies Infectieuses, &c," 

 Strasbourg, 1866, and Paris, 1872. 



f " Comptes Rend, de l'Acad. des Sc.," Paris, Feb. 1, 1869, et passim. Also 

 " Bull. Acad. Med.," Paris, 1872, p. 907, &c. 



X Or, as it was termed, " generations," with reference to the microphytes found 

 to be present in the blood of these cases, which w r ere regarded as constituting the 

 active contagium, and which by propagation in the blood of living animals, it was 

 said, acquired " renewed vigour " in successive generations. I have retained this 

 term " generations " as convenient, but without here implying anything more than 

 successive inoculations from one animal to another. 



§ As by H. Dreyer, " Archiv. f. Expt. Path. u. Pharm." 1874, Bd. II, s. 149, &c, 

 and Clementi and Thin. 



|| Lot: tit, "Bull. d. l'Acatl. de Med.," 1873, p. 124, &c. 



