756 



oxygen of carbonic acid can not be. used for this purpose, and he 

 believes that no decomposition of tlie absorbed carbonic acid takes 

 place. Exact determinations by Schlosiug of the oxygen absorbed 

 during the period of nitrification show the supply to be sufficient for 

 the oxidation which takes place. 



The synthesis of organic matter from inorganic compounds in the 

 presence of chlorophyll is a most familiar fact. It has been assumed 

 that this synthesis occurs in vegetable organisms only in the presence 

 of chlorophyll with the aid of the sun's vays or equivalent source of 

 energy, as, for instance, electric or other artificia llight. The possibility 

 of life without organic matter was suggested by Heraeus, though his 

 experiments did not prove it. It was advocated by Hueppe, who 

 attributed it to nitrifying ferments which could cause the union of the 

 elements of carbon dioxide and water to form carbohydrates, and could 

 do this even in diffused sunlight. For this process he used the phrase 

 "chlorophyll action without chlorophyll." 



Winogradsky's experiments show that the nitromonas has the power 

 of assimilating the carbon of carbonic acid and building up its own 

 substance in entire absence of organic matter and in entire darkness. 

 In other words, we have here the complete synthesis of organic matter 

 by the action of living organisms without the aid of the energy of the 

 sun's rays. 



The questiou as to the oxidation of nitrogen to nitrous or to nitric 

 acid by the nitrifying ferment has been studied by Wiuogradsky as by 

 Schlosiug and others. In brief it appears that in soils with sufficient 

 aeration and temperature and other conditions favorable to oxidation, 

 nitric acid is the main product, but with inadequate oxygen supply, low 

 temperature and excess of alkali considerable nitrous acid is formed. 

 Wiuogradsky found that in h'quid cultures the quantity of ammoniacal 

 nitrogen oxidized increased with the amount of oxygen (air) accessible, 

 but the nitrous fermentation prevailed and but little nitric acid was 

 formed. 



The relation between the quantities of nitrogen oxidized and carbon 

 assimilated was observed by Wiuogradsky in four liquid cultures, free 

 from organic matter at the outset. From 33.3 to 3Q.6, or on the aver- 

 age 35.4 mg. of nitrogen were found in the forms of nitrous and nitric 

 acids for each mg. of organic carbon, i. e. carbon of the nitro-bacteria 

 dev^eloped while the oxidation took place. The fact that this relatiou 

 was so nearly the same in the diflerent trials although the conditions 

 varied widely can hardly be without significance. 



As regards the nature of the synthesis of organic matter by the nitro- 

 bacteria, Wiuogradsky is iii(;lined to the belief that some sort of an 

 amide compound is formed in the culture at the expense of the carbonic 

 acid absorbed (from the carbonate or the air) and the ammonia in th« 

 solution. Urea suggests itself iu this connection, since this substance 

 is formed both artificially and synthetically in the animal organism by 

 the union of carbonic acid and a<mmouia, Certain \)acteria are already 



