7 6 



THE SPIRIT OF THE SOIL 



with strong Hydrochloric acid, and a flocculent 

 brown precipitate obtained. This was filtered off, 

 redissolved in ammonia, reprecipitated, and washed. 

 The Humic acid so obtained was divided into two 

 portions. The first was dried in a steam oven at 

 100 C., while the second was purified by boiling for 

 an hour under a reflux condenser with absolute 

 alcohol. These two portions were analyzed, and the 

 following figures were obtained : 



It will be noticed that after purification with 

 alcohol the natural Humic acid was closely com- 

 parable with that obtained from Dextrose, as can 

 be seen from the table : 



This does not mean that a real formula can be 

 written for Humic acid, for it is well known that the 

 Carbon content of Humic acid does vary with the 

 substances from which it has been prepared, but it 

 emphasizes that a very close similarity exists between 



