2 4 o SCIENCE PROGRESS 



must resemble more closely the synthetic processes by which 

 alkaloids are formed in the higher plants. 1 



In the case of two bases, namely those represented by the 

 formulae C 7 H U N (isolated by Gautier and Mourgues from cod- 

 liver oil and regarded by them as hydrolutidine) and C 8 H n N 

 (obtained by Oechsner de Coninck from putrid cuttlefish), 

 evidence of heterocyclic structure has been advanced, as it is 

 stated that they are converted by oxidation to pyridinecar- 

 boxylic acids. It would be particularly interesting to know the 

 precursors of these bases. 



When entire organs or tissues are putrefied, bases may be 

 formed from substances other than the proteins contained in 

 them. A considerable number of bases occur in muscle (meat 

 extract) which may undergo change on putrefaction. Thus 

 kreatine is converted by putrefaction into methylguanidine and 

 possibly also into dimethylguanidine ; the purine and pyrimi- 

 dine derivatives in nucleic acid doubtless also contribute to the 

 formation of bases obtained on putrefaction of the pancreas ; 

 the choline of lecithin is set free on putrefaction and in its turn 

 gives rise to trimethylamine. It is thus evident that when an 

 entire organ is putrefied a very complex mixture must be formed 

 and few of the bases can be isolated in sufficient quantity for 

 a thorough investigation ; one is often restricted to the analysis 

 of gold or platinum salts. 



A further difficulty in the investigation of putrefaction bases 

 is obvious. The working up of large quantities of material is apt 

 to be so unpleasant that it cannot be undertaken in most 

 laboratories. The initial operations can only be carried on out 

 of doors and even after the more volatile malodorous substances, 

 like skatol and mercaptans, have been got rid of, the smell of 

 butyric acid and its homologues clings tenaciously to the 

 investigator. 



As a result of this condition of affairs, a large number of 

 bases have been described which have not been chemical en- 

 tities ; sometimes the same base has been described under as 

 many as four or five different names. There is also a good 

 deal of confusion, especially in the minds of the general public, 

 with regard to the physiological effect of ptomaines. 



1 Pyridine bases are not infrequently present in the commercial amylic alcohol 

 used in the extraction of ptomaines. This contamination has not always been 

 guarded against. 



