96 * The Organic Matter of Soil. [August, 



Another class of vegetable acids, which are also produced by 

 the action of oxygen on organic matter, is called the azotized, 

 from the fact that they contain nitrogen. These acids are the 

 crenic and apocrenic of Berzelius. Both are soluble in water and 

 alcohol; the apocrenic less so than the crenic. They form with 

 alkalies and alkaline earths soluble and insoluble salts; some of 

 which arc essential 'constituents of a rich and productive soil. 



By the continued absorption of oxygen from the atmosphere, 

 wood and other organic matters are converted into a nutriment for 

 vegetables. The crenic and apocrenic acids are products of 

 bodies which are nitrogenous themselves; the nitrogen of which 

 is retained through all the changes which the organic matters 

 pass. 



It seems to be established, then, that organic matter may be 

 useful to plants, and may promote their growth in various ways. 

 This conclusion might be made almost a priori, subsequent to the 

 determination of the nature of the bodies under consideration; for 

 it is well known that many bodies require nitrogen; and it is as- 

 certained that some of the organic bodies contain, and others ab- 

 sorb and retain ammonia obstinately. And each of these classes 

 of bodies are soluble, and in a condition to be received into the 

 vegetable system. 



If the foregoing considerations are true, why should farmers be 

 taught that the organic matter of decaying leaves and of their barn 

 yards is useless? that it is a bad economy to spread it upon their 

 fields, or plow it into their soil? We have sometimes won- 

 dered why it is that many intelligent farmers hold book farm- 

 ing in such low repute. We, however, have been satisfied as to 

 the cause; when, for instance, doctrines are taught so contrary to 

 their experience; and when they are told that they had better 

 burn their barn yard manure rather than carry it out to their 

 meadows, we are not at all surprised that they lose confidence in 

 books, and hence often refuse to receive many things which are 

 really sound and valuable; and this, on account of the erroneous 

 doctrines which come apparently from a responsible source. 



But to return to the consideration of ammonia in the soil. 

 Chemists are not agreed as to the processes by which ammonia 

 is supplied to the soil. That it exists there, and that it is pro- 

 vided for by certain chemical changes is admitted. W'e have 

 stated in a former article in this journal, that one of the means 

 by which it is restored to the soil is through the mutual influence 

 of water and the protoxide of iron; the latter substance having 

 the power of decomposing the former and taking to itself its oxy- 

 gen; the hydrogen being liberated instantly combines with the 

 nitrogen of the air in the soil, and forms with it ammonia. 

 Humic acid, too, by its strong affinity for ammonia, rapidly ab- 



