ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
239 
Bactericidal Action of Tannin.* * * § — Prof. G. Goegg records a large 
series of elaborate experiments with tannins of various derivation on 
five microbes, for the purpose of testing their bactericidal properties. The 
microbes were B. anthracis, B. pyocyaneus , B. coli. com., B. prodigiosus, 
St. aureus ; and the tannins, aspidospertannic, coffee-tannic, catechu- 
tannic, gallic, kino-tannic, rhatany-tannic, and tannic acids. Extract of 
rkatany and kino resin were also used to determine the difference 
between the pure tannins and preparations containing tannin. The 
author’s work clearly establishes that officinal tannin is less energetic 
than other tannins termed physiological. Aspidospertannic acid, for 
example, is far more bactericidal than officinal tannin. Hence there is 
some relation between the bactericidal action and the remarkable tan- 
ning action which Quebracho Colorado (from which aspidospertannic 
acid is obtained) has in the leather industry. 
Kino-tannic acid acts more powerfully than the kinos themselves ; and 
rhatany-tannic acid exerts a considerable bactericidal action on B. pyo- 
cyaneus and St. py. aureus. Spore-forming bacteria appear to be little 
sensitive to the action of tannin ; on the other hand, St. py. aureus is 
extremely so. 
Mechanism of Immunity imparted by Anti-coagulating Sub- 
stances. f — MM. Bose and Delezenne made experiments relative to the 
immunity imparted by anti-coagulating substances. They found that 
leech extract or pepton, when injected into the blood, is able to produce 
certain modifications which increase the defensive powers of the organ- 
ism against infectious agents. These modifications are characterised by 
a remarkable increase in the vitality and phagocytic properties of the 
white corpuscles, and by augmentation of the bactericidal power of the 
blood. The intravenous injection of the anti-coagulating substances into 
rabbits and dogs 15-45 minutes before the injection of coli bacillus or of 
Streptococcus , is able to confer on these animals a real immunity, and 
even to impart an action absolutely inhibitory against experimental 
infection. 
Bacteriology of Plague.J — Herr Kolle states that the pus in the 
bubos contains bacilli with rounded ends. Both ends stain deeply, the 
central portion hardly staining at all. This bacillus is also found in the 
blood and in the spleen. It does not stain by Gram’s method. On 
agar the colonies are whitish grey ; on gelatin, which is not liquefied, 
they are light brown and finely granular. In grape-sugar bouillon the 
organism thrives. No spore-formation was observed. The cultures are 
killed in a few minutes at 100°, and at 58° in a few hours. 
iEtiology of Dysentery .§ — Dr. W. Janowski concludes, from an 
exhaustive review of 84 works on dysentery by different writers, that 
this disease is the result of a co-operation of several parasites, and is not 
due to the pathogenic action of a single microbe. Two varieties of 
•dysentery are distinguished, the ordinary malady caused by the associ- 
* Ann. de Micrographie, ix. (1897) pp. 49-144. 
t Comptes Rendus, cxxiii. (1896) pp. 500-3. 
X Deutsch. Med. Woekenschr., March 4, 1897. See Brit. Med. Journ., Epit., 
April 3, 1897, p. 56. 
§ Centralbl. Bakt. u. Par., l te Abt., xxi. (1897) pp. 88-100, 151-8, 194-202, 234-55. 
