522 SCIENCE PROGRESS 



Kocher in the Bern hospital. An investigation was made of 

 the bacteria found in the fistula and also of the excreted products. 

 None of the ordinary protein putrefaction products, such as 

 indol and skatol, were discovered, and furthermore, it was shown 

 that there was always excess of acid present. The conditions 

 were not favourable to the development of bacteria (as had 

 been shown by a previous research in Nencki's laboratory by 

 Madame Sieber), and Nencki with his co-workers on this 

 research (Macfadyen and Madame Sieber) came to the con- 

 clusion that bacteria were not necessary for the utilisation 

 of proteins in the alimentary tract. Nuttall and Thierfelder, 

 by direct experiment, subsequently arrived at the same con- 

 clusion. 



Another series of important investigations was undertaken, 

 with the object of determining the relation of aerobic to 

 anaerobic growth. It was shown that under anaerobic con- 

 ditions the nutrient medium serves as a source of oxygen 

 supply; under these conditions, furthermore, oxidation does 

 not proceed so far. The results obtained were in accordance 

 with what might be expected from the equations already given 

 to represent the various processes. 



Nencki also investigated the action of various bacteria on 

 carbohydrates. He succeeded in demonstrating the important 

 fact that, whereas some species of bacteria will produce an 

 inactive lactic acid, others produce an active form. The relation 

 of these stereochemical forms to living bodies remains to-day 

 one of the great mysteries of biochemical action. Not less 

 interesting were Nencki's researches on the preparation of 

 products from proteins and carbohydrates of products obtained 

 originally by means of micro-organisms by chemical means. 

 He showed, for example, that skatol and indol could be obtained 

 from proteins by fusion with potash, and that hydrogen, which 

 is also often a product of putrefactive action was evolved at 

 the same time. 



Special interest attaches at the present time to Nencki's 

 studies on the decomposition of sugars and other bodies in 

 the presence of oxygen at body temperature. He showed that 

 glucose, for example, in the presence of alkaline hydroxides 

 at the temperature of 40 yields relatively large quantities 

 of lactic acid. This body is probably a normal degrada- 

 tion product of the sugars, for it is excreted in the urine 



