458 



Mr. G. F. Dowdeswell. 



[Jan. 18, 



this case, too, there occurred an increase in the infective virulence of 

 the pathogenic fluids, in successive generations of transmitted infec- 

 tion, similarly to the case considered hereinbefore. The remarkable 

 circumstance here shown of the origination of an infective bac- 

 terium-containing product by means of a chemical irritant, seems 

 to have been since lost sight of in reference to its bearings on 

 the question of the relations of micro-organisms to infective 

 disease. The affection was first described under the title of the 

 " Infective Products of Inflammation;" but recently a similar disease 

 has attracted attention under the designation of Pasteur's septi- 

 chsemia, a term which is decidedly a misnomer,* the blood neither in 

 the living animal nor shortly after death, to my experience, being in 

 anywise infective or septic. I have found in numerous experiments 

 made since those herein recorded, some of which have lately been 

 communicated to the Royal Society, that these two forms of disease, 

 which may be originated by various methods, are essentially the same, 

 inasmuch as they are interchangeable at will, merely by altering the 

 place of injection, the pathological symptoms in both are similar, only 

 differing in extent and severity ; the serous exudation in each has a 

 very similar character, though the subcutaneous oedema is more con- 

 stantly highly coagulable than the peritoneal exudation, the period of 

 incubation after inoculation is similar, and the micro-organisms 

 which occur in each are identically the same, vaguely as they are 

 characterised by recent French writers. f 



Guinea-pigs were used in this case, healthy animals being selected ; 

 for comparative experiments young and as much as possible of the 

 same size. To originate infection, a small quantity of a dilute solu- 

 tion of ammonia was injected by means of a Pravatz syringe into 

 the peritoneal cavity of one of these animals ; the water used was 

 previously boiled, the syringe was new, rinsed out with boiling water, 

 and the vessels employed were disinfected by heat. In subsequent 

 experiments with infective fluids the syringes after use were treated 

 first with boiling water, then with a strong solution of potassic per- 

 manganate, and again washed in boiling water ; that these measures 

 were sufficient to destroy infection was proved by several experi- 

 mental injections with these syringes of normal saline solution, which 

 in every instance were innocuous. I have found guinea-pigs as well 

 suited as rabbits for experiments on this affection, and although 

 here, as is shown, the period of incubation is somewhat less constant 



* It has since been styled by Dr. R. Koch more appropriately " malignant 



oedema." 



f M. Pa stem*, howerer, shows that he is familiar with the microscopical characters 

 and measurements of these organisms, " Bull. Acad. Med.," 1881, p. 97. and from 

 this passage and other circumstances it seems to me shown that the " new disease " 

 therein referred to as a form of rabies, is identical with Davaine's septichaemia. 



