OF WATER FOR ORGANIC MATTER. 53 



falling, nevertheless, over many rocks, is always clearer, 

 although the reason partly of this is, that such water is 

 not surface only, but has drained through the soil. 



Peat itself, if distilled with fixed alkalies, gives out 

 ammonia. I suppose there is no doubt that some of this 

 arises from the decay of vegetable albumen, some of which 

 may be retained in the peat ; but its mode of decomposition 

 is still a problem ; it seems to take place chiefly by oxida- 

 tion, not putrefaction. I was inclined to think that a 

 notable amount of this alkali may be taken by the acid 

 waters direct from the atmosphere. 



The smoke of peat, or rather the oily matter deposited 

 by the smoke, contains nitrogen compounds, very pro- 

 bably the bases obtained by the decomposition of the 

 vegetable albumen, which will not enter into fermentation, 

 or expand itself into the lower and dreaded organized forms, 

 although compelled to yield to the action of fire. 



I give a few quotations from ^Mulder's Physiological 

 Chemistry,^ first German edition : — 



" I repeat that the ammonia in the soil, as in the 

 natural saltpetre-grottos of Ceylon, is formed from the 

 atmospheric air, the oxygen of which, instead of forming 

 nitric acid, changes the organic substances into ulmic 

 acid, then into humic acid, geic acid, apocrenic acid, and 

 into crenic acid.'^ 



P. 158. "This formation of ammonia from the consti- 

 tuents of the air and water is of the highest importance 

 for the growth and success of the plant. It is the cause 

 which converts the insoluble organic constituents of the 

 soil into soluble substances, and thus presents them to 

 plants as organic food, even when no ammoniacal manures 

 are added besides to convert the five mentioned acids into 

 soluble salts of ammonia.^^ 



P. 166. "Ulmic, humic, and geic acids, however formed, 

 possess the power of absorbing ammonia and water to the 



