QEBONTIN. 449 



tained about 3.2 per cent, yield of the acid, and of this about two- 

 thirds was levo-rotatory, the remainder being inactive. On heating 

 with baryta under pressure the active form is changed into the inac- 

 tive. 



The free acid melts at 203-206° (198° Wildstatter) with decom- 

 position and gives off an odor of pyrrolidin. This odor is also noted 

 during the evaporation of a solution. It forms flat needles which 

 effloresce. Owing to its marked solubility in water and in alcohol 

 it was overlooked in previous studies of casein. It gives with phos- 

 photungstic acid a crystalline precipitate which easily dissolves on 

 boiling. 



The active form unites in alkaline solutions with phenyl isocyanate 

 to form a cyanate, the anhydrid of which readily crystallizes and 

 melts at 143°, whereas that from the inactive form melts at 118°. 



On boiling with freshly precipitated copper oxid the acid forms 

 the easily crystaJlizable salt (C5HjN02)2Cu + 2H2O, which is espe- 

 cially useful for the isolation of the acid. The salts of both active 

 and inactive forms possess the same properties. 



The ethyl ester boils at 75° — 76° at 11 mm. pressure. It was by 

 fractional distillation of the esters of the monamino acids which re- 

 sult in the hydrolytic cleavage of proteids that this acid was isolated 

 by Fischer. 



Gerontin, CgHj^N^, is a base which was isolated by Grandis in 

 1890. It has been repeatedly observed in the form of peculiar crys- 

 tals found in the cell nuclei in the liver and kidneys, particularly of 

 old dogs. The free base is an isomer of cadaverin, etc., and re- 

 sembles it somewhat. It crystallizes in needles which are readily 

 soluble in water and alcohol ; possesses a strongly alkaline reaction, 

 and yields the ordinary alkaloidal reactions. 



The hydrochlorid forms prismatic crystals, which are deliquescent 

 and easily soluble in alcohol. 



The platinochlorid, C5Hj^N2.2HCl.PtCl^, is soluble in water and 

 crystallizes in spindle-shaped needles, arranged in rosettes. It de- 

 composes at 115°. 



The gold salt forms small needles, and is easily soluble in water 

 and alcohol. 



It combines with one molecule of mercuric chlorid to form deli- 

 quescent cubes or rectangular prisms containing two molecules of 

 water of crystallization. It decomposes above 100°. This distin- 

 guishes it from cadaverin, which combines with three to four mole- 

 cules of mercuric chlorid. The crystals observed in the liver are 

 probably the phosphate. 



The new base also yields a benzoyl compound which melts at 

 175°-176°. 



It seems to exert a paralyzing action upon the nerve-centers and 



29 



