312 A MANUAL OF BACTERIOLOGY 



the odour of hawthorn, especially when heated. 

 This ptomaine forms crystalline double salts with 

 the chlorides of platinum and gold. 



It appears that the ptomaines just described be- 

 long to, or are derivatives of, the pyridine series of 

 organic bases. 



Neuridine (C 5 H 14 N 2 ). This ptomaine was dis- 

 covered by Professor Brieger as a constant product 

 of the bacterial putrefaction of albuminous sub- 

 stances. Its hydrochloride, platinochloride, and 

 aurochloride have been obtained in the crystalline 

 condition ; but the free base is so unstable that it 

 has never been obtained pure. A solution of sodium 

 hydroxide decomposes neuridine hydrochloride into 

 dimethylamine and trimethylamine. 



Saprine (C 5 H 14 N 2 ). This base is isomeric with 

 the preceding, but differs from it in the solubilities 

 of its salts, and probably also in chemical constitu- 

 tion. It was discovered by Brieger in 1883. 



Cadaverine (C 5 H 14 N 2 ). Brieger isolated a third 

 isomeride from albuminous substances subjected to 

 prolonged putrefaction. This base is also readily 

 formed in cultivations of Finkler's spirillum. Dr. 

 Ladenburg l proved that this ptomaine has all the 

 chemical and physical properties of pentamethyl- 

 enediamine. It is a non-poisonous liquid with an 

 alkaline reaction. This base boils at 115 C., and it 

 has the odour of conicine. 



Putrescine (C 4 H 12 N 2 ) is usually found accom- 

 panying cadaverine, but makes its appearance 



1 Berichte der deutschen chemischen Gesellschaft, vol. xix. 

 p. 2586. 



