SECTION VIII. 



DECOMPOSITIONS AND TRAN.sR >KM ATH >.\S <>K ORGANIC 

 NITROGENOUS COMPOUNDS. 



CHAPTER XXX. 



THE PHENOMENA OF PUTREFACTION. 



168. The Degradation of the Albuminoids. 



IN 15 of the Introduction it was stated that Liebig's differentiation between 

 fermentation and putrefaction is untenable, and that no sharply defined limit 

 between these terms exists. Enlarging the definition of the term fermentation 

 beyond its usual limits, we there defined this phenomenon as the transformation 

 of various chemical substances by the action of minute fungoid organisms. 



Without prejudice to this general definition, we can nevertheless speak of 

 putrefaction in particular, limiting the application of this term to such fermen- 

 tations as chiefly effect the decomposition of albuminoid substances. Any further 

 attempt to analyse this more restricted term is at once frustrated by our igno- 

 rance of the constitution of the albuminoids themselves. The multiplicity of 

 contingencies here possible cannot be disregarded, and consequently no classifica- 

 tion according to the final products obtained is feasible. On the other hand, no 

 differentiation can be based on the composition of the bodies subjected to decom- 

 position, since we are here encountered by a question, hitherto unsolved by 

 chemists, viz., What are the albuminoids? 



Obviously mycologists might postpone further researches on this point until 

 the necessary preliminaries have been performed by their chemical colleagues. 

 As a matter of fact, however, the opposite course has been adopted, and the 

 determination of the nature of the putrefaction products of albumen has not 

 only led to hypotheses regarding the composition of that substance, but will 

 probably also indicate the means whereby the nature and synthetic preparation 

 of these high-molecular nitrogen compounds can be established. Provided the 

 results obtained are of value to the chemist, and, though in a minor degree, to 

 the mycologist as well, the credit thus accruing to Fermentation Physiology is 

 not necessarily injured by the remark that, owing to the employment of indefinite 

 bacterial mixtures, these endeavours are not always free from objection from a 

 bacteriological point of view. 



In future researches into albuminoid decomposition or putrefaction, it should 

 always be borne in mind that here also the co-operation and succession of various 

 organisms (i.e. symbiosis and metabiosis) will have to be taken into calculation. 

 Until this is done, mycological text-books will have nothing better to offer than 

 a varied collection of isolated observations, such as are given in the following 

 chapters and paragraphs. 



It has lontr l )( .,. n ohsorvod that the natural decomposition of albumen yields 

 malodorous ^ascs and vapours when proceeding in the absence of air. but that, 

 on the other hand, these attendant phenomena are wanting when air is allowed 



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