AMINES DERIVED FROM PROTEIN 19 



cheese prepared in the usual manner, but not in a cheese prepared 

 with chloroform milk, so as to ensure sterility. The normal cheese 

 was found to give off considerable quantities of carbon dioxide during 

 ripening and Van Slyke and Hart consider that the carbon dioxide 

 arose from the decarboxylation of amino-acids. The chloroformed 

 cheese produced only traces of carbon dioxide and when finally 

 analysed yielded a considerable quantity of arginine, while the 

 normal cheese contained only traces of arginine, but instead of it 

 guanidine and putrescine were present. The cavities in Emmenthaler 

 ("Gruyere") cheese are mostly filled with carbon dioxide, and 

 p-hydroxy-phenyl-ethylamine was isolated from this kind of cheese by 

 Winterstein and Kiing [1909]. 



It is further almost certain that one of Brieger's ptomaines, mydine 

 [1886, i, p. 26], was identical with p-hydroxy-phenyl-ethylamine. The 

 base had the composition C 8 H n NO, yielded a soluble platinichloride, 

 and a picrate crystallising in broad prisms melting at 190. It was ob- 

 tained from putrid human viscera, and was non-poisonous ; ferric and 

 gold salts were reduced by it. (The picrate of the synthetic amine 

 crystallises in " short prisms " melting at 200 ; the other properties 

 are identical with those described for mydine by Brieger.) 



The physiological action of p-hydroxy-phenyl-ethylamine was first 

 brought to light by its identification, by Barger and Walpole [1909, i], 

 as the chief pressor constituent in extracts of putrid meat. The blood 

 pressure raising property of such extracts had already been observed 

 by Abelous, Ribaut, Souli6, and Toujan [1906, i, 2], Dixon and 

 Taylor [1907] had also noticed that extracts of human placenta raised 

 the blood pressure on intravenous injection and caused, in addition, 

 contraction of the pregnant uterus. Rosenheim [1909] showed that 

 this effect was mot produced by extracts of perfectly fresh placenta, 

 and after Barger and Walpole's identification of the pressor con- 

 stituent of putrid meat, he was further able to show that the active 

 constituent in Dixon and Taylor's placental extracts was also p- 

 hydroxy-phenyl-ethylamine. Finally this amine is the chief pressor 

 constituent of certain extracts of ergot, as shown by Barger and Dale 

 [1909]. A certain quantity is apparently present in perfectly fresh 

 ergot, where it has also been found by Engeland and Kutscher [1910, 2] 

 and by Burmann [1912]. p-Hydroxy-phenyl-ethylamine is pro- 

 bably also present in autolysed Boletus edulis (Reuter [1912]). That 

 tyrosine is indeed the parent substance of p-hydroxy-phenyl-ethylamine 

 was shown by Barger and Walpole [1909, I]; the yield in putrefaction 

 was minute (less than i per cent, of the tyrosine present). Ackermann 



