ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
237 
(“ Rausclibrand ”). As is well known, guinea-pigs are extremely sensi- 
tive to Rausclibrand, while rabbits are almost completely refractory. 
Yet these bacilli develope better in the blood-serum of rabbits than 
in that of guinea-pigs. By vaccination the blood-serum of both animals 
is found to have received increased germicidal properties ; nor is this a 
transitory condition, for the authors observed it for seventy days. 
Hence for Rausclibrand no parallel can be drawn between the natural 
resistance of these animals and the germicidal property of their blood- 
serum. 
Germicidal Action of Blood.* — Prof. J. von Fodor, after alluding to 
his first researches on the germicidal action of blood, the experiments 
and inferences of others on the exact value to be given to the plasma, 
the corpuscles, or the tissues in destroying bacteria, and therefore pro- 
ducing immunity for the organism, gives an account of some lengthy 
researches he has recently carried out on the same subject. 
The bacterium employed was anthrax, and the blood of living 
animals was passed, with the usual precautions, into flasks containing 
glass beads. The blood was then defibrinated by shaking and afterwards 
inoculated with anthrax disseminated equally throughout the blood 
by means of the beads. At certain intervals some of this blood was 
inoculated on pepton-gelatin. 
Only some of the results of the more important experiments can be 
mentioned. These were that arterial blood is more germicidal than 
venous ; and fresh blood more so than that which has stood. 
The germicidal action increases with the temperature, being strongest 
from 38°-40°, after which it rapidly diminishes. 
Individual disposition to infectious diseases seems to be in exact 
proportion to the germicidal action of the blood. 
By artificial modification of the blood, in other words by increasing 
its alkalinity, it was found that the germicidal properties would be 
considerably augmented. It therefore immediately followed that it 
might be possible, by increasing the alkalinity of the organism, to 
inhibit the growth of anthrax after inoculation, and experiments were 
made on rabbits with this intent, by injecting them with bicarbonate of 
soda. The results were sufficiently satisfactory to warrant a further 
and more prolonged investigation. 
Certain Conditions that modify the Virulence of Tubercle-Bacillus. f 
— Dr. A. Ransome has made some experiments that go to show that fresh 
air, light, and a dry sandy soil have a distinct influence in arresting the 
virulence of the tubercle-bacillus; mere exposure to light in otherwise 
bad sanitary conditions does not destroy the virus. 
Cure for Tetanus and Hydrophobia. Mr. E. H. Hankin has a 
notice of a recent memoir by Behring and Kitasato, two workers in 
Prof. Koch's laboratory, who have not only succeeded in producing 
immunity against diphtheria and tetanus, but also in curing animals 
affected by these diseases. The most remarkable part of their discovery 
is the fact that the blood of an animal that has been made immune 
* Centralbl. f. Bakteriol. u. Parasitenk., vii. (1890) pp. 753-G6. 
t Proc. Roy. Soc. Lond., xlix. (1891) pp. 66-73. 
% Nature, xliii. (1890) pp. 121-3. 
