458 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
proportion of tlie urea and carbonate of ammonia. The effective organ- 
isms are not specifically designated, hut are merely called cocci and 
bacilli. 
New Theory of Immunity.* — According to Herr Pfeiffer, none of 
the explanations of the immunising action of cholera serum are satis- 
factory, and he suggests that the immunising matters in the serum 
represent a kind of preliminary stage of the bactericidal substances, just 
as the glycogen present in the body is the predecessor of glucose. Like 
the grape-sugar, the bactericidal substances are easily destructible — even 
warming up to 55° is sufficient. In case of need the animal body has 
the power of rapidly forming them from the inactive substances of the 
serum. 
Immunity to Cholera. f — In an investigation as to the difference of 
susceptibility of certain animals and man towards the cholera vibrio, 
Drs. C. Fermi and A. Salto considered the question from the following 
points : — The reaction of the intestinal contents ; the substances of 
which these contents are composed ; the intestinal atmosphere ; the 
flora of the intestine and of the intestinal mucosa. The reaction of 
the intestinal contents appears to possess a certain influence, and iu 
the faeces of animals refractory to cholera there exists a substance which 
possesses an inhibitory effect. The intestinal gases seem to have no 
influence. The intestinal flora exerts an unmistakable influence, and this 
is almost exclusively due to Bac. coli commune. The healthy intestinal 
mucosa has a distinctly inhibitory action on the cholera vibrio. 
Saltpetre-decomposing Bacillus.J — Herr J. Schirokikh isolated from 
fresh horse-dung a bacillus which liquefies gelatin and acts energetically 
on the nitrate salts. The organism was easily obtained by making 
gelatin plates from suspensions in bouillon and then inoculating agar 
plates from the liquefying colonies. The bacillus has rounded ends, is 
nearly twice as long as thick, and forms chains of from 2-8 links. It 
is mobile, is easily stained, and is an essential aerobe. It grows fairly 
well at room temperatures, but its optimum is 37° *5. It liquefies 
gelatin. On agar the growth is usually white, on potato brownish. 
On bouillon a white scum forms, the subjacent medium being stained 
yellow. It forms spores in great numbers. Wheniinoculated in bouillon 
which contains 2*5 grm. KN0 3 per litre, the salt is decomposed at a 
temperature of 30°-35° in 5-8 days. 
Varieties of Diphtheria Bacilli.§ — Mr. E. A. Peters read a paper 
before the Pathological Society on the varieties of diphtheria bacilli, of 
which four kinds were described. The points of difference exhibited by 
early cultures were as follows : — (1) Long Klebs-Loeffler bacillus. A 
twenty-four hours’ old culture on blood-serum showed short bacilli, long 
segmented forms *003 mm. in length, long-clubbed bacilli, and short 
clubs. This form was pathogenic to guinea-pigs, with long retention 
of virulence. (2) Short bacilli, the twenty-four hours’ cultures of which 
showed large numbers of conical bacilli *0015 mm. in length, and a 
* Deutsche Med. Wochenschr., 1S96, Nos. 7 and 8. See Centralbl. f. Bakteriol. 
u. Parasitenk., l te Abt., xix. (1896) pp. 575-9. 
f Centralbl. f . Bacteriol. u. Parasitenk., l te Abt., xix. (1896) pp. 525-36. 
X Op. cit., 2 te Abt., ii. (1896) pp. 201-7. § Lancet, 1895, ii. pp. 1576-7. 
