^ETIOLOGY OE TUBERCULOSIS. 
15T 
material in the interior of the syringe and especially that clinging to the punctur¬ 
ing apparatus. Hence the syringes must have a special construction which makes 
their disinfection by heat possible. For this purpose the syringe must be made 
of glass and metal. The lower end of the same must be made to have an air-tight 
connection with the framework of the needle by means of a cork plate, set 
in and bored through; and the piston must be wound with a soft cotton thread. 
In this form the syringe can, before every experiment, be made free from infec¬ 
tious germs by an hour’s heating at 150° to 160° C. The piston is then moistened 
by absorbing boiled distilled water, and if the enwrapping ig done with some care, 
it becomes as tight as by the use of the ordinary leather or gutta percha piston.* 
The hands of the experimenter are to be disinfected with a one percent, sublimate 
solution, and of course everything else is to be avoided which could lead to an 
unintentional infection of the animal to be experimented on during or after the 
operation. 
By all the attempts at infection to be mentioned in what follows, the pruden¬ 
tial measures just explained were strictly carried out and, therefore, to speak again 
of the latter, for every attempt several freshly bought animals were used and kept 
in separate cages, the effect of the infection was proved so early, that a confusion 
with the later appearing spontaneous tuberculosis could not occur; further, the 
tuberculous changes appearing in consequence of the infection were always studied 
with reference to the presence of tuberculous bacilli, and where it seemed neces¬ 
sary, also especially with reference to their infectious qualities. The infection 
itself took place with antiseptic precaution and especially with reliably disinfected 
instruments. 
The attempts at infection carried out in the course of my investigations re¬ 
garding tuberculosis fall into two groups. To the one group belong those attempts 
in which tuberculous bacilli-bearing parts of tissue were used; to the second, those 
in which reinculturen of tuberculous bacilli were the infectious material. 
E.—ATTEMPTS AT INFECTION WITH TUBERCULOUS BACILLI- 
BEARING TISSUES. 
These served partly for studying the effects of the products of various sorts 
of tuberculous processes, partly to gain suitable sowing-material for the beginning 
of reinculturen. As inoculating material there were used pieces of tissue from 
various organs of human miliary tuberculosis, from phthisic lungs, various forms 
of localized tuberculosis, from fungous joints, scrofulous glands, lupus, tuberculosis 
of various animals. The inoculating material was always examined with reference 
to its contents of tuberculous bacilli. The inoculation took place in this manner: 
In guinea pigs a small cut was made with the shears into the belly and by the use 
of the points of the shears a pocket-shaped subcutaneous wound about one half 
ctm. deep was made in this cut. Into this little skin pocket a little piece of the 
inoculating substance, varying in size from a grain of millet to a mustard-seed, 
was pushed in as deeply as possible. On the following day the inoculation wound 
always appeared closed and showed no reaction. Usually a noticeable swelling 
of the lymph-glands lying next to the point of inoculation, usually of the inguinal 
glands on one side, first appears after two weeks and at the same time a harden- 
*Syringes of this construction are furnished by H. Windier, court instrument maker, 
Berlin, N. W. Dorotheenstrasse 3. 
