THE FERMKNTATION TUBE WITH SPECIAL REF- 

 ERENCE TO ANAEROBIOSIS AND GAS PRODUC- 

 TION AMONG BACTERIA. 



By THEOBALD SMITH. 



Ill the study of the microscopic forms known as bacteria we 

 have what might be fitl3' called the focal point of the various 

 branches of biological science. Though their investigation 

 may require careful morphological researches yet the unmis- 

 takable monotony of form, combined with a considerable vari- 

 ation of physiological activity, has compelled the bacteriologist 

 to pay much attention to means by which such physiological 

 variations may be more or less accurately registered in order 

 that they may serve as a supplementarj' basis for classifica- 

 tion. Again, with unicellular organisms the manifestations 

 of cell activity become the most important phenomena for 

 study. These manifestations bring together the fields of 

 physiology and chemistr}' and make bacteriolog3- in one sen.se 

 a branch of phj-siological chemistry. 



In dealing with bacteria and the results of their activity, one 

 fact strongly impresses us and that is the necessity of knowing 

 precisely and unmistakably the organism before us. No mat- 

 ter how profound the physiological and chemical studies of 

 bacterial life, unless they are linked to an organism readily 

 identifiable they have failed to assert their full value. In all 

 the investigations of bacteria in their relation to the fermenta- 

 tion industries, to the dairy, to the soil, and to human and 

 animal diseases now going on, the element of fundamental im- 

 portance is the organism itself. About this all functions are 

 grouped, to this every question fin all}' reverts. The necessity 

 for more accurate means of recognizing species and varieties 

 has, however, not generally been felt and the methods of diag- 

 nosis have not kept pace with progress in the more practical 



