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 an 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 1890, 
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 avian 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 Héricourt 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 0.05, 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 tomend. The vascularity is less, the whitish spots of fibrinous material 
