79 6 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
competent observers have failed to find these remains, and the explana- 
tion offered is that the tissue has been improperly hardened and im- 
perfectly stained. 
Natural Immunity to Anthrax.* — In discussing the vexed question 
of natural immunity to anthrax, Dr. G. Sanarelli alludes first to the 
historical aspect of the subject, and then shows how he obtained lymph 
free from germs and leucocytes. A carefully sterilized glass rod from 
5-6 mm. thick was dipped 4-5 times in a 5 per cent, solution of col- 
lodion, and then the collodion having dried, the little bag thus formed 
was closed by putting some more collodion on the opening. With a 
little dexterity, a large number of these capsules, 3-4 cm. long and 
holding 1-2 ccm., can be made in a short time. They are transparent, 
impermeable, and perfectly aseptic. They are filled by introducing them 
into the dorsal lymph-sac of a healthy frog, and there leaving them for 
3-4 days, by which time the collodion capsule becomes filled by transu- 
dation. The lymph is then pipetted into suitable glass vessels. With 
this fluid numerous experiments were made touching the bactericidal 
qualities of lymph, and the influence of temperature on the germicidal 
property. These experiments were conducted in the usual manner, 
and from the results obtained the author concludes that frog’s lymph 
perfectly free from germs and leucocytes does attenuate anthrax, but 
that such attenuated virus does not acquire vaccinal properties. The 
germicidal action of lymph is lost if the fluid be heated, but cold 
appears to possess little or no detrimental influence. On anthrax 
bacilli frog’s lymph exerts a degenerating influence, and this quite 
independently of any assistance from leucocytes. With regard to 
phagocytosis the action of the cell-element is not regarded with disfavour, 
but the author inclines, and rightly, to make immunity depend upon the 
comb ned influence of the plasma and cell elements of the blood, rather 
than on the unaided action of any separate constituent. 
Immunization against the Virus of Tetanus.f — Prof. G. Tizzoni and 
Dr. G. Cattani divided their experiments with the tetanus bacillus into 
two series. In one they examined into the effect of various chemical 
substances on the tetanus virus. The only agents which possessed any 
active influence were carbolic acid, chlorine water, and trichloride of 
iodine. The first of these was used in 5 per cent, solution, and the 
iodine trichloride in 2 per cent, solution. All three agents, allowed to 
act on equal volumes of filtered tetanus cultivations for twenty-four hours, 
destroyed the toxicity of the virus altogether. But none of these 
substances, when injected subcutaneously either before or after the 
inoculation of the virus, was able to prevent the tetanus phenomena. 
In the second series the authors made use of animals which they had 
found to be more or less refractory to the tetanus poison (pigeons and 
dogs). In fact, the pigeons used by the authors showed only local 
transitory phenomena, recovering after injection of a moderate quantity 
of a virulent tetanus cultivation completely in a shorter or longer time. 
And every succeeding injection produced less and less reaction, until the 
animals ceased to react altogether. In a similar way dogs may be 
* Centralbl. f. Bakteriol. u. Parasitenk., ix. (1891) pp. 4G7-72, 497-504, 532-9. 
t Tom. cit., pp. 189-92. 
