ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
759 
Micro-organisms of Fresh Vegetables.* — Although the researches 
of Pasteur, Fernbach, Buchner, and others have shown that under 
normal circumstances no bacteria are present within vegetable tissues, 
Dr. Fazio has examined fresh vegetables, such as fennel, celery, 
lettuce, and endive, in order to ascertain if micro-organisms existed in 
the interspaces of the buds and leaves. With this object the plants 
taken from the garden were first externally purified, then superficially 
charred, and then pieces removed under proper antiseptic precautions 
with a kind of cork-borer. The pieces were placed in test-tubes con- 
taining bouillon, and left for 24 to 48 hours. If obvious clouding 
occurred, then further examination was made with gelatin plates. In 
this way four kinds of saprophytic bacteria were constantly demon- 
strated. 
Resistance of Spores to High Temperatures. - !* — Dr. Lewith, from a 
series of experiments, finds that the increased resistance of spores to dry 
heat is due to the fact that, during their formation, an inspissation of the 
protoplasm occurs from loss of water. From experiments with egg- 
albumen, he estimates that the most resistant spores contain about 10 
per cent, of water ; but, stated from a practical point of view, that is, 
for disinfection purposes, the proportion nearly amounts to this, the less 
the amount of water in the spores and the more impenetrable the spore- 
membrane, the greater is the resistance of the spores. Hence, for com- 
plete disinfection by heat, moisture is of importance. This, too, holds 
good for disinfection with chemical substances, such as sulphuric acid, 
chlorine, bromine, and sublimate, for they can only properly act in the 
presence of water. 
Influence of Carbonic Acid and other Gases on the Development of 
Micro-organisms. J — Mr. P. F. Frankland exposed plate-cultivations of 
Bacillus pyocyaneus, cholera spirilla, and Finkler’s spirilla in a simple 
apparatus to the action of carbonic acid, carbonic oxide, sulphuretted 
hydrogen, sulphurous acid, hydrogen, nitrous and nitric oxide. It was 
found that three kinds of bacteria were quickly killed by NO, H 2 S, and 
S0 2) that CO and N 2 0 acted less vigorously than C0 2 , and that they 
were least affected by H. With regard to the experiments with carbonic 
dioxide, it was found that B. pyocyaneus recovered perfectly when 
exposed to the air, but that the other bacteria did not — a result contrary 
to that obtained by Fraenkel. 
Resistance of living Bacteria and Yeast-cells to Pigments.f — The 
resistance shown by the living spores, of e. g. B. anthracis and subtilis , to 
the inception of watery solutions of anilin dyes, says Herr H. Buchner, 
disappears, as is well known, after their death. A similar condition of 
things is presented by the vegetative cell, and the behaviour of these 
cells to watery solutions of anilin pigments opens up several interesting 
questions. 
Three series of experiments are given, in all of which methyl-violet 
* Rivista Internaz. d’lgiene, i. (1890) pp. 1-3. See Centralbl. f. Bakteriol. u. 
Parasitenk., vii. (1890) p. 798. 
t Arch. f. Exper. Pathol, u. Pharmakol., xxvi. p. 3H. See Centralbl. f. Bakteriol, 
u. Parasitenk., vii. (1890) p. 477. 
+ Zeitschr. f Hygiene, vi. (1889). See Bot. Centralbl., xlii. (1890) pp. 273-4. 
§ Centralbl. f. Bakteriol. u. Parasitenk., vii. (1890) pp. 733-6. 
