xii INTRODUCTION 



complex crystalline bodies, and gummy substances, by the 

 oxidation of isobutyraldehyde by potassium permanganate or 

 potassium dichromate under the given conditions of temper- 

 ature and relative concentrations of the reagents. The material 

 at hand likewise shows that one of the immediate needs in the 

 field of zymology is the development and consistent use of 

 adequate analytical methods for the fermentation products. 



The names ascribed to the microorganisms by the various 

 investigators have been listed as they are given in the original 

 communication. In case the generic or specific designation has 

 been changed since that time the later name has been cross- 

 indexed. The use of an author's name for an organism has 

 been given to identify it. When the statement is made that a 

 certain organism was used to produce definite products, no 

 attempt was made by the authors of this index to judge the 

 purity of the culture. The technique in many instances has 

 not been such as to warrant the conclusions which have been 

 drawn with regard to the ability of the organism to bring about 

 the action reported. It is unfortunate that occasionally 

 investigators will execute a very careful piece of research from a 

 chemical point of view and fail to describe the organism with 

 which the work was done, merely referring to it as a "bacillus." 

 Reference to a number of publications has been omitted for 

 this reason. Frequently a description of an organism has been 

 given which may be adequate for purposes of classification but 

 no name has been attached. The authors wish to emphasize 

 the importance of a proper use of bacterial taxonomy in 

 chemical studies of fermentation. 



The results of the literature survey made with the limita- 

 tions above outlined are presented in three Tables involving 

 the four items: organism, substrate, product and authority. 

 In Table i they are shown in the order named above. This 

 compilation enables the reader to gain an idea of the general 

 chemical actions of a given organism and to compare them with 

 others. In Table 2 the order is substrate, product, organism, 

 authority, enabling the reader at a glance to gain an idea of the 

 various products elaborated from a given substrate by the 

 organism involved. It is of interest to note that the products 



