EXTRACTS FROM EXCHANGES. 
337 
as a rule. The author seems to incline toward the aetiological 
identity of the disease with human diphtheria for the following 
reasons : a —A few cases of human diphtheria occurring in the 
families of owners of such infected poultry seem to point to this 
deduction, b —Antidiphtheritic serum seemed to exert a favor¬ 
able influence upon the diseased poultry, c —Through the cour¬ 
tesy of Prof. Krmenghem, he is enabled to report the finding of 
a short bacillus, identical to the so-called pseudo-diphtheria ba¬ 
cillus, which, however, inoculated into guinea pigs had not the 
slightest effect upon them. The author considers this bacillus 
to be an attenuated diphtheria bacillus. His experiments are, 
therefore, not sufficient or conclusive enough to prove the origin 
of human diphtheria from an aviary soiirce, although such a 
transmission is a probable one.— (^Berl. TJuerd^^zt, IVych.) 
Koch’s New Tuberculin —In the Munchner 
Allgevi. Zeitung B says: Koch’s new tuberculin offers better 
prospects of success than his old tuberculin did, because he was 
more careful this time and did not, as he did formerly, limit his 
observations to infected animals merely, but made his observa¬ 
tions on infected people also. The method of preparation of the 
new remedy bids fair to improve the results of its application in 
proper cases, because the new remedy is an entirely different 
product from the old one and must, therefore, necessarily give a 
different reaction. The old tuberculin obtained by the heating 
of cultures contained inflammatory and fever-producing ele¬ 
ments, but not a single substance capable of producing immuni¬ 
zation in the living body, as B. and his pupils conclusively 
showed. In order to produce a better tuberculin it obviously 
was necessary to obtain the bacillary contents directly and un¬ 
altered ; the only difficulty lay in the carrying out of this ^ pro¬ 
ject in the case of such small bodies as the tubercle bacillus. 
Koch’s new tuberculin practically contains the contents of the 
tubercle bacilli unchanged, which contents, it is to be hoped, 
will immunize (if not cure) persons against tuberculosis.” 
Koch’s Method.—He first dries the tubercle bacilli; they are 
then finely rubbed 5 water is then added to obtain the bacillary 
contents in solution. Buchner and his pupils claim that they 
can produce a better tuberculin in the following way : Koch 
claiming that his new tuberculin cannot be improved upon, B. 
mechanically rubs the living bacilli in the moist (not dry) state 
with fine sand or gravel in order to avoid the accumulation of 
dust and then obtains the bacillary contents by means of a press¬ 
ure of 400 to 500 atmospheres ; he presses out the contents; 
