316 CHEMISTRY OF THE PTOMAINS. 



Gadinin (from Gradus callarias, haddock) in small doses does not 

 appear to be poisonous ; large doses (0.5—1 gram) are decidedly toxic 

 and may kill guinea-pigs. The formula of the free base as deduced 

 from the analysis of the platinochlorid may be either C,II,.NOj or 

 C,H„NO,.OH. 



The hydrochlorid, CyHjyNOjj.HCl, as obtained by the decomposi- 

 tion of the platinochlorid with hydrogen sulphid, crystallizes under 

 the desiccator in thick, colorless needles, which are easily soluble in 

 water ; insoluble in alcohol. It forms no combination with gold 

 chlorid, but does give crystalline precipitates with phosphomolybdic, 

 phosphotungstic and picric acids. 



The platinochlorid, (CjHj,]Sr02.HCl)2Pta,(Pt= 27.68 per cent.), 

 is at first quite soluble, and on standing in a desiccator it crystallizes 

 in golden-yellow plates which, when once formed, are again difficultly 

 soluble in water. It can be recrystallized from hot water. It melte 

 at 214°. 



Typhotoxin, C,Hj,NOj. — This base was named thus by Brieger 

 in 1885 (III., 86), and was regarded by him as the specific toxic 

 product of the activity of Koch-Eberth's typhoid bacillus. It is 

 however, certain, as in the case of tetanus, that the real poison of this 

 germ is not this ptom^in, but rather a toxin. He obtained the base by 

 cultivating the bacillus on beef-hash for eight to fourteen days at 

 37.5°— 38°. The nature of the soil on which the bacillus grows has 

 a great deal to do with the formation of the poison. An espe- 

 cially important factor is the temperature, for Brieger observed that 

 no poison was produced in one case where the temperature remained 

 by accident at 39° for twenty-four hours. Under such conditions 

 creatin is present in quantity, whereas otherwise the reverse is the rule. 



In the process of extraction (p. 232) it occurs in the mercuric chlo- 

 rid precipitate, and from this it is obtained, after the removal of the 

 mercury by hydrogen sulphid, as an easily deliquescent hydrochlorid. 

 This for the purpose of purification is converted into the difficultly 

 soluble aurochlorid. 



Typhotoxin is isomeric with gadinin and the compound C^Hj^NOj 

 which Brieger obtained from putrefying horse-flesh. In its properties 

 it is, however, very different. Thus, the free base is strongly alka- 

 line, and its hydrochlorid yields a difficultly soluble picrate. On the 

 other hand, the isomer from horse-flesh possesses a slightly acid 

 reaction, and does not form a picrate. Again, typhotoxin gives with 

 Ehrlich's reagent (sulphodiazobenzol) an immediate yellow color, 

 which disappears upon the addition of alkali, whereas the isomer does 

 not yield this reaction. Furthermore, the two bases differ in their 

 physiological action and in their behavior to alkaloidal reagents (see 

 Table I.). Their aurochlorids, however, possess the same melting- 

 point. 



