22 Natur e of Humus [Oct. 



It is well known that humus improves the physical condition of 

 the soil. It increases, for instance, a soil's capacity to hold water, 

 to retain valuable nitrogenous constituents, to resist corrosion. It 

 binds the particles of sandy soils. It makes clayey soils friable, 

 increasing at the same time their capacity to absorb the sun's raya 

 and rendering the soil-temperature more uniform. In other words, 

 humus makes the soil a more habitable and suitable home for the 

 Performance of the life functions of plants. 



Thus, we find the humification process inserted into the chaln of 

 nature's cycles as a necessary link, without which the perpetual con- 

 tinuance of plant life cannot be conceived. Again, man's food, 

 whether of vegetable or animal origin, is composed chiefly of pro- 

 teins, fats, carbohydrates and mineral substances, all of which are 

 contained in the plant and animal bodies. However, animal life is, 

 in the last analysis, based upon the presence of plants, the digestion 

 and assimilation of which give the material for the formation in 

 the animal body of its organs and tissues. Again, the plants need 

 for their life certain elements which are present in humus. Here 

 we have, then, a cycle in which the physical life of man, as well as 

 the existence of the animal and vegetable kingdoms, are brought into 

 close connection with humus. So close is this relation thatconditions 

 indispensable for life are also necessary for decomposition of humus 

 materials; extremes that exclude life also render decomposition im- 

 possible. There is practically no plant life in arctic regions or 

 throughout the winter, and there is no decomposition under the 

 same conditions. On the other hand, plant life is luxuriant in the 

 tropics. There, too, decay is very rapid. The plant and the animal 

 kingdoms need air for their life. The same air is indispensable for 

 decomposition. Equally, neither plant life nor decomposition of 

 organic substances is possible without water. 



In the process of humification, nature has a powerful means for 

 the utilization of vast amounts of waste materials for purposes of 

 life. Or to put it in other words: It is the humification of vege- 

 table and animal remains that makes them available for new genera- 

 tions of plants. 



