572 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
important difference being that they developed at a lower temperature, 
the optimum lying between 23° and 25°. The bacillus is aerobic, and 
develops freely in bouillon, forming a copious sediment, the bouillon 
remaining clear. On potato it forms a whitish fragile layer having about 
the consistence of soap. Serum or agar cultures 9-10 days old showed 
dichotomously branching bacteria with pointed ends. These forms were 
obtained only with difficulty. Gelatin was not liquefied. The bacteria 
were motionless. 
Products of the Tuberculosis Bacillus * — Drs. E. A. de Schweinitz 
and M. Dorset have isolated from liquid cultures of the tubercle bacillus, 
a crystalline substance having a melting point of 161°-164°, readily 
soluble in water, ether, and alcohol, and separating from these solutions 
in needle-like or prismatic crystals with a slight yellow tint. They did 
not give the biuret reaction. The solution is acid in reaction and taste, 
and optically inactive. There is no precipitate with silver nitrate, 
platinum chloride, or barium hydrate. Analysis gave a formula closely 
corresponding to C 7 H 10 O 4 , or teraconic acid, an unsaturated acid of the 
fatty series. The medium contained potassium acid phosphate, ammo- 
nium phosphate, asparagin, and glycerin. Injection of these crystals into 
the liver of guinea-pigs produced necrotic areas, and it is therefore pro- 
bably the substance responsible for the coagulation necrosis so frequent 
in tuberculosis. It is also a temperature-reducing principle in healthy 
and diseased animals. The fever-producing substance of tuberculosis 
was extracted by means of hot water, the extract being found to contain 
an albuminoid which caused the tuberculin reaction in guinea-pigs and 
calves upon repeated injections. The authors infer that the reason why 
tuberculin does not react continuously is the joint presence of these two 
bodies. 
Saprophytic Form of Human and Avian Tuberculosis.f — MM. 
Bataillon and Terre, who discovered a bacillus having close affinities 
with that of tuberculosis, inoculated intraperitoneally carps, lizards, 
and frogs with young cultures ; positive results were obtained from these 
cold-blooded animals, while guinea-pigs and pigeons were found to be 
refractory. Thinking that this germ, originally derived from a tumour 
on the belly of a carp, might be an altered form of tuberculosis, the 
authors, in order to test this view, fed carps on the viscera of tuberculous 
guinea-pigs. 
After eight or nine days bacilli were found swarming in the liver, 
and in eleven days bacilli were isolated from the frog which were 
morphologically and culturally identical withjthose previously described. 
But guinea-pigs injected with an emulsion of the carp’s liver remained 
quite healthy. Human tubercle bacilli inoculated on frogs failed to 
develop ; but from avian bacilli excellent results were obtained after a 
passage of 15 days. 
The authors conclude that the form described is a saprophytic 
variety of tuberculosis, and one which can be reproduced by passing 
human or avian tuberculosis through cold-blooded animals. 
* Centralbl. Bakt. u. Par., I te Abt., xxii. (1897) pp. 209-21 (1 pi.). 
t Comptes Bendus, cxxiv. (1897) pp. 1399-1400. 
