ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
577 
5-7 days, and later on firm, the white being liquefied. Acetate of lead 
papers demonstrated the development of sulphuretted hydrogen, and the 
reaction of the medium became faintly acid. In 3^-4 weeks the vibrios 
were dead. V. Metschnikovi behaved in much the same way, but the 
other spirilla did not grow well or develope H 2 S in the eggs. 
From the albumen infected by the different species of Spirilla , injec- 
tions were made into the peritoneal sacs of guinea-pigs, each receiving 
0 * 5-5 ccm. of cultures 1-2 weeks old. V. cholerse and V. Metschnikovi 
set up well-marked toxic phenomena; but though the others induced 
pathological symptoms the animals recovered. 
The toxines were separated from the eggs by precipitation with 
alcohol and extracting them from the dried precipitate with water. The 
aqueous extract was repeatedly treated with alcohol-ether, then with 
ether only, and finally dried in a vacuum-exsiccator. The cholera and 
Metschnikovi toxines were pale brown and easily soluble in water ; they 
gave the biuret and xantho- protein reactions, a red colour with Millon’s 
reagent, and on the whole behaved chemically like peptones. The 
phenomena excited by the injection of these aqueous extracts were very 
similar, except that that from V. Metschnikovi was more rapid and stronger 
in its action. Injection of the albumen itself was followed more rapidly 
by morbid phenomena than when the aqueous extract was used. An 
effective toxin was also obtained from V. Finkler-Prior, while the pro- 
ducts of V. Deneke and aquatilis were but little toxic. 
Cholera Vibrio and Hens’ Eggs.* — The results obtained by Herr W. 
Donitz from cultivating the cholera vibrio on hens’ eggs were chiefly 
that, when alone, these organisms do not form sulphuretted hydrogen in 
quantity perceptible to the smell or demonstrable by means of lead paper ; 
and also that the hens’ egg is a very unsuitable medium for pure cultures 
of bacteria. The eggs used were as fresh as possible ; for the ordinary 
bought eggs almost invariably contained germs which produced sulphu- 
retted hydrogen. Formalin was tried as a disinfectant, but it was found 
that when it had been used too long the eggs became useless as nutrient 
media, nor is it to be recommended as a preservative, for when opened 
the egg sets to a glassy mass. 
Formation of Poisonous Substances by Vibrios in Hens’ Eggs.f — 
Herr Bonhoff has cultivated Vibrio danubicus, berolinensis , and Dunbar in 
hens’ eggs for the purpose of determining whether poisonous substances 
were formed in the cultivation medium, and if so whether these sub- 
stances were protective against intra-peritoneal inoculation of cholera. 
In the result the author found that all these vibrios had the same action 
on the egg-albumen, and that watery extracts of alcoholic precipitates of 
these eggs contained the same poisonous substances, but not in the 
same quantity ; a well-marked immunity which lasted for 15-36 days 
against intraperitoneal injection of living cholera vibrios was obtained 
from the egg extractives. Hence it appears to be probable that the toxic 
substances formed by vibrios in egg-albumen are identical. 
* Zeitschr. f. Hygiene u. Infektions., xx. p. 81. See Centralbh f Bakteriol. u. 
Parasitenk., l te Abt., xvii. (1895) pp. 892-8. 
t Arch. f. Hygiene, xxii. (1895) pp. 851-91. 
