31 



skatol, indol, acids, glycols, etc. The formation of nascent 

 hydrogen by the action of destructive organisms on car- 

 bohydrate and proteid compounds may be best illustrated by 

 a careful study of the products obtained by the destructive 

 distillation of coal, wood and other products of animal and 

 vegetable origin. In the destructive distillation of coal we 

 get as products: 2 , H 2 , N 2 , S 2 , Cx, H 2 0, NH 3 , H 2 S, CH 4 , CO, 

 C0 2 , C 2 H 2 , C 2 H 4 , C 6 H 6 , CS 2 , etc. All of these products are 

 obtained in small or large amounts depending on the com- 

 position of the coal, character of heating, etc. Can these 

 products be explained in any other way than that the complex 

 proteid molecules undergo in this process of destructive dis- 

 tillation, complete disintegration into their constitutent 

 elements: C, 0, H, N, S.? These elements must exist mo- 

 mentarily in the active or nascent state. Because of their 

 great chemical affinity these active elements then combine 

 with each other to form inactive molecules which are free to 

 pass off from the sphere of action. In the formation of these 

 simple molecules some of the atoms have combined with 

 different atoms, while some have combined with other 

 atoms of the same kind. As a result of the first method 

 we get: H 2 0, NH 3 , H 2 S, CO, C0 2 , C 2 H 4 , CH 4 , etc. As a 

 result of the second method we get: Cx (coke or soot), N 2 , H 2 , 

 2 , S 2 , etc. 



For the reduction of nitrates in pure culture, a medium 

 consisting of peptone 1% and potassium nitrate 1% was em- 

 ployed. 10 cc of this medium were introduced into each 

 tube and sterilized. These tubes were inoculated with the 

 various organisms and incubated at 33C for ten days. At 

 the expiration of this time they were tested for the presence 

 of nitrates and nitrites. The presence of nitrate was deter- 

 mined by the addition of a 1% solution of diphenylamine in 

 pure concentrated sulphuric acid. The nitrite was deter- 

 mined according to the method used in the previous work 

 on impure cultures. Those cultures which failed to reduce 

 nitrates to nitrites within ten days were duplicated and the 

 time extended to thirty days for a final reading. 



The organisms in the following list were obtained from the 

 celebrated Krai collection, Vienna Austria, Prof. Kraus Cura- 

 tor; and from the American Museum of Natural History, 



