366 PROTECTIVE INOCULATIONS. 



venous injections of cultures of the bacillus of tuberculosis in fowls. 

 Animals which had been so treated after an interval of two to six 

 months received an intravenous injection of one cubic centimetre of a 

 culture of the bacillus tuberculosis from man. This was fatal to 

 " non-vaccinated " dogs, as a rule, in about three weeks, but the " vac- 

 cinated " animals survived the injection. 



The results obtained by Trudeau (1893) are of such interest that 

 we shall quote in extenso what he says with reference to preventive 

 inoculations : 



" Antitubercular inoculation was first tried by Falk in 1883, and all 

 attempts in this direction have resulted until recently in but uu unbroken 

 record of failures. In 1890 I added my name to the list of those who found 

 it impossible to produce immunity in animals by this method. In 1S1K), 

 Martin and Grancher, and Courmont and Dor, claimed to have produced in 

 rabbits a certain degree of immunity by previous inoculation, after Pasteur's 

 hydrophobia method, of aviaii tubercle bacilli of graded and increasing viru- 

 lence. These vaccinations were, however, frequently fatal to the animals, 

 and the immunity obtained was but slight. Richet and He'ricourt have since 

 claimed to produce complete immunity in dogs by intravenous inoculations 

 of bird tubercle bacilli. These experimenters found that though harmless to 

 the dog when first derived from the chicken, bird bacilli, by long cultivation 

 in liquid media, become pathogenic for this animal, and by thus grading the 

 virulence of the injections complete immunity against any form of tubercu- 

 lar infection was produced in the dog. As yet these striking results have not 

 been confirmed. The animals which I now present to you illustrate an at- 

 tempt I have made along the same line to produce immunity in the rabbit. 

 Cultures grown directly from the chicken's lesions in bouillon for, first, five 

 weeks, then six months, were twice injected subcutaneously at intervals of 

 twenty-one days in doses of 0.025 and 005, and a third injection of a still 

 older culture was occasionally given. About one in four of the rabbits died 

 within three months, profoundly emaciated, but without any visible tubercu- 

 lar lesions. The remaining animals recovered aud were apparently in good 

 health, when, together with an equal number of controls, they were inocu- 

 lated in the anterior chamber of the eye with cultures of Koch's bacillus 

 derived from the tuberculous lesions of the rabbit, and cultivated about three 

 months on glycerin- agar. The results of these inoculations present many 

 points of interest. In the controls, as is usually the case, if the operation 

 has been done carefully and aseptically, and with a moderate amount of 

 dilute virus, two days after the introduction of the virulent material in the 

 eye little or no irritation is observed, and little is to be noticed for two weeks, 

 when a steadily increasing vascularity manifests itself, small tubercles ap- 

 pear on the iris, which gradually coalesce and become cheesy, intense iritis 

 and general inflammation of the structures of the eye develop, the inocula- 

 tion wound becomes cheesy, and in six to eight weeks the eye is more or less 

 completely destroyed and the inflammation begins to subside. The disease, 

 however, remains generally localized in the eye for many months, and even 

 permanently. In the vaccinated animals, on the contrary, the introduction 

 of the virulent bacilli at once gives rise to a marked degree of irritation. On 

 the second day the vessels of the conjunctiva are tortuous and enlarged, 

 whitish specks of fibrinous-looking exudation appear in the iris and in the 

 anterior chamber, and more or less intense iritis supervenes ; but at the end 

 of the second to the third week, when the eyes of the controls begin to show 

 progressive and steadily increasing evidence of inflammatory reaction, the 

 irritation in those of the vaccinated animals begins slowly to subside and the 

 eyes to mend. The vascularity is less, the whitish spots of fibriiious material 



