98 BACTERIOLOGY. 



complished in the existing condensation of the 

 molecnle. Asparagin, as compared with form- 

 aldehyde and ammonia, is one degree nearer to 

 proteid. Conversely, asparagin arises out of 

 proteid through oxidation. Schiitzenberger 

 by artificially decomposing proteid, obtained a 

 body related to succinic acid which had the em- 

 pirical formula C 4 H 7 NO 2 . Low considered this 

 body as formed by molecular rearrangement of 

 the hypothetical aldehyde of aspartic acid or of 

 amido-succinic acid (C 4 H 7 NO 4 = CH 2 .COOH. 

 CHNH 2 .COOH), and has represented its prob- 

 able significance in the building up of proteid 

 in the formula already given (p. 93). Accord- 

 ing to Low's conception, the chemical basis for 

 the reactivity of active proteid lies in the associ- 

 ation side by side, as shown in - the foregoing 

 formula, of the very reactive aldehyde and 

 amido groups. For this reason, also, all those 

 bodies which attack these two groups are 

 protoplasmic poisons (cf. p. 85). It has been 

 .ascertained by Neelsen, Naegeli and Hueppe 

 that asparagin is one of the best substances for 

 the nutrition of bacteria, and that these organ- 

 isms can construct out of it organic pigments 

 and also, as Uschinsky has lately determined, 

 proteid-like poisons. The nutritive value of 

 asparagin is such that even some warm-blooded 

 animals, such as cattle, can make use of it to 



