334 



ANNUAL REPORT OF THE 



Off. Doc. 



The following is a list, after Rideal,^ of the amido acids which 

 have been found as products of the putrefaction of proteids: 



The amido acids are next decomposed into ammonia and organic 

 acids as shown in the last column of the above table. Tyrosin 

 breaks into indol, phenol and skatol. 



Of the basic products of putrefaction we have non-volatile bases 

 known as ptomaines and leucomaines, produced in minute quanti- 

 ties, and certain volatile bases such as monomethylamine and tri- 

 methylamine. These latter basic products by further decoipposi- 

 tion are converted into ammonia. 



From the preceding it is seen that the final products of putrefac- 

 tive fermentation are ammonia and organic acids. Naturally the 

 organic acids will combine with the ammonia to form salts, but these 

 salts will undergo a still further change in which the acid is con- 

 verted into carbon dioxide, hydrogen and marsh gas. The two latter 

 escape while the carbon dioxide combines with the ammonia to form 

 carbonate of ammonia. This completes the process, the proteid 

 matter resolving itself into two gases, hydrogen and marsh gas, 

 with a solid residium in the form of ammonium carbonate. 



Theoretically this is true, but in reality there remains as a "by- 

 product" of these reactions, as Rideal puts it, "a varying but small 

 quantity of dark pulverent matter resembling the humus or peaty 

 substances of soil." 



In addition to this it is known that under certain conditions of ex- 

 clusion of air, and of the development of the more strongly anae- 

 robic bacteria, a certain amount of the nitrogen escapes in the free 

 state before it is converted into ammonia. While this takes place in 

 putrefying fluids such as sewage it probably does not occur to any 

 appreciable degree in soils. 



According to Sommaruga, aerobic bacteria growing in non-sac- 

 charine nutrient media always form an alkali from albuminous 

 bodies. These alkaline bodies so far as known are either ammonia 



