566 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
action strictly speaking, but rather a pliagolytic process whereby the 
vibrios are destroyed. 
Resistance of Spores of Bacteria to High Temperatures.* * * § — Dr. P. 
Miquel and M. E. Lattraye, who have made a large number of experi- 
ments as to the resistance offered by spores of bacteria to moist 
heat above 100° 0., find that in some exceptional cases a temperature of 
100° cannot be relied on to sterilise nutritive media containing micro- 
organisms from the earth, air, or water, unless the temperature be kept up 
for five hours or more. This is not only not practical, but causes changes 
in the gelatin. Recourse should be had to cold-sterilising, by means 
of the porcelain bougie, or to heat of 110°Jfor a quarter of an hour. 
The method of sterilising by discontinuous heating is based on an inexact 
theoretical conception ; for to sterilise discontinuously at 100° requires 
almost the same time that one continuous heating does. If at below 
100°, e. g. at 60°, 70°, 80°, media have been successfully sterilised by 
discontinuous heating, this has been due to the fact that they do not con- 
tain spores of those bacteria which do not resist a temperature of 70°-80°. 
In disinfecting by high-pressure steam it is better to prolong the action 
to twenty minutes, and to slightly exceed 110°, as germs are more 
resistant to mere steam than when immersed in water or any cultiva- 
tion medium. 
Influence of High Temperature on Bacillus mesentericus vul- 
gatus.f — The results of the observations of Dr. A. Wroblewski on 
Bacillus mesentericus vulgatus, when exposed to high temperatures, show 
that this bacterium is completely or almost completely killed off if the 
medium be heated thrice for 20 minutes each time to a temperature of 
80°, with pauses of 12 hours at 38°-40°. Little effect is produced if the 
temperature be slowly raised, and practically none at all if the medium 
be suddenly cooled. 
Bactericidal Effect of Silver Salts.J — Dr. H. Kionka reports on the 
work which has been done by Behring, Schaffer, Meyer and others as to 
the disinfecting value or bactericidal influence of solutions of certain 
silver salts — Argentum-casein, silver nitrates, and Argentum-amin. 
The < ffect seems to be generally inhibitive to the life of bacteria, as 
many different kinds were experimented with ; but it is strongest against 
Gonococcus. The poisonous effect of the silver is slight, as the doses 
used in practice are very small. In penetrating power the salts are 
effective in the order mentioned above. 
Bacteria of the Leguminosae-Tubercles.§ — -According to Herr M. 
Gonnermftnn, the root-tubercles of Leguminosee are not formed by a 
single species of bacterium, the kind varying according to the local 
position and the nature of the ground in which they are cultivated. The 
* ( sprout forms” which arise in the plant as the result of symbiotic and 
parasitic conditions, and which later break up into separate bacilli on 
* Ann. cle Microgr., vii. (1895) pp. 205-18. 
f Centralbl. f. Bakteriol. u. Parasitenk., 2 te Abt., i. (1895) pp. 419-22. 
t Biol. Centralbl., xv. (1895) pp. 519-26. 
§ Landwirthsch. Jahrb., xxiii. (1894) pp. 649-71. See Bot. Centralbl., lxii. 
(1895) p. 260. - 
