168 
R. KOCH. 
there developed iritis suppuration of the bulbus, followed by rapid emaciation. 
In the case of the second rabbit, on the contrary, the eye remained unchanged in 
the beginning and not until the second week did there appear single white yellow¬ 
ish knots on the iris in the neighborhood of the point of injection, and proceeding 
from this a typical iris tuberculosis developed itself. New little knots constantly 
appeared on the iris, the iris laid itself into ray-shaped folds, but the cornea gradu¬ 
ally became cloudy and thereby hid the other changes from view. The animals 
were killed after thirty days. The first was perfectly healthy; in the second, 
aside from the already mentioned changes in the eye, the lymph-glands on the jaw 
were found swollen and permeated with yellow-white herds, the lungs and other 
organs were still free from tuberculosis. The two last rabbits had again number¬ 
less tubercles in the lungs. 
Fifteenth experiment: Reincultur of miliary tubercles from a human lung 
(No. 4) cultivated for four and one-half months in eight successive breedings, was 
rubbed up with blood serum and the needle of a syringe filled with it and pricked 
into the anterior eye chamber of six rabbits without, however, making an injection. 
In all the animals iris tuberculosis developed, in some of them a slowly spreading 
infiltration of the conjunctiva with tuberculous knots, reaching beyond the neigh¬ 
borhood of the point of inoculation. Two of the animals of this experiment killed 
after four weeks had already caseously infiltrated lymph-glands on the neck, but 
still no tubercles in the lungs. The other rabbits were killed after eight weeks 
and more or less numerous tubercles were then also found in the lungs. 
At various times rabbits received injections of reinculturen intheanterior eye 
chamber in order to test the influence of substances, which hinder the development 
of tuberculous bacilli in these animals. Of these attempts which, as has already 
been mentioned, I carried on with Dr. Gaffky, a report will be given on a later 
occasion. It may be said here in passing, that beside numerous other means, 
arsenic,* helenin, sulphuric hydrogen, and moreover always in the largest possible 
doses and for weeks at a time, were used upon the animals. We cannot state a 
favorable effect of one of these means in a single case. All the animals perished tu- 
berculously just as quickly as those which had not been treated with meanshinder¬ 
ing development. The infection took place in various ways; partly by simple 
inoculation (comp, experiments 7 and 8) partly by injection into the eye-chamber, 
partly by injection into a vein. The rabbits infected from the eye-chamber concern 
the following cases: 
Sixteenth experiment: Reincultur of miliary tubercles of the human lung 
(No. 22) cultivated for eight months in ten successive breedings, rubbed up with 
distilled water and injected into the anterior eye chamber of two rabbits ; Rein¬ 
cultur from a phthisic lung (No. 1) cultivated for thirteen months in twenty-one 
successive breedings, injected in the same way into fifteen rabbits. Some of the 
same reincultur one month later injected into six rabbits. All these rabbits perished 
* The use of arsenic to fight tuberculosis has been often recommended in former times 
and tried by many physicians. It was therefore natural to test the influence of this on tu¬ 
berculous animals. Our experiments occurred almost a year before the recommendation 
of arsenic by Buchner appeared, and were, therefore, not induced by that. According to 
Korab, helenin has prevented tuberculosis and sulphuric hydrogen was warmly recom¬ 
mended bv Froschauer. 
