CHAPTER XIV. 



CHEMISTRY OF THE PTOMAINS. 



The basic substances described in the following pages are ar- 

 ranged, as far as possible, in the regular natural order. An inspec- 

 tion of the list of these bases will show the remarkable fact of the 

 predominancy of the amine type. Almost two-thirds of the known 

 ptomains contain only C, H, and N, and represent simple ammonia 

 substitution compounds. Of the oxygenated bases, all of those 

 whose constitution is known possess the trimethylamin group as 

 their basic constituent, and it is quite probable that most, if not all, 

 of the remaining ptomains will be found to possess the same or a 

 similar basic nucleus. 



It will be seen, furthermore, that a very large number of the 

 ptomains described possess little or no toxic action, and are, therefore, 

 physiologically inert. It would seem, as Brieger has already pointed 

 out, that a certain quantity of oxygen is necessary to the formation 

 of poisonous bases. A free supply of oxygen, on the other hand, in- 

 variably yields non-toxic ptomaiins. The poisonous bases begin to 

 appear about the seventh day of putrefaction, and in turn disappear 

 if this is allowed to go on for a considerable period of time. 



It has already been pointed out that the ptomains are to be regarded 

 as extra-cellular products of bacterial activity. They do not origi- 

 nate within the bacterial cell and therefore they are not to be looked 

 upon as direct metabolic products of the cell protoplasm but rather 

 as secondary cleavage products. The production of amines and di- 

 amines, for example, is clearly due, as in the case of monamino acids 

 leucin and tyrosin, to the splitting off of preexisting groups in the 

 substance acted upon. This fact has been made especially clear in 

 the demonstration of the origin of putrescin and cadaverin from the 

 proteid bases arginin and lysin ; and of cholin and allied bases from 

 lecithin. 



Methylamin, CHj.NHj; this is the simplest organic base that 

 is formed in the process of putrefaction. It is ammonia in which 

 one atom of hydrogen has been replaced by the methyl radical. It 

 occurs in herring-brine (ToUens, 1866 ; Bocklisch, 1886) ; in decom- 

 posing herring, twelve days in spring (Bocklisch) ; in pike, six days 

 in summer (Bocklisch) ; in haddock, two months at a low tempera- 

 ture (Bocklisch) ; in the fermentation of cholin chlorid (Hasebroek). 

 Brieger found it present in cultures of comma bacillus on beef-broth 



248 



