FOREST CHEMISTRY. 73 



essary materials for crop growing. The forest is, therefore, the chief source 

 of soil fertility, costing us nothing except care for the trees. In view of its 

 inestimable value Humboldt exclaimed: "How foolishly man destroys the 

 forest cover without any regard for consequences, for thereby they rob 

 themselves of wood and water!" 



EVOLUTION OF MOISTURE. 



Chemistry is evolving this great truth, that the vegetable kingdom is 

 primal in the orders of life; that, while dependent on its co-factors for its 

 existence, in contributing to their support it thereby supports itself. The 

 vegetable kingdom is in fact an essential medium of that universal chem- 

 istry, by which, with the sun administering to all in reciprocity, water is 

 evolved. We might as well say that the constituents of the tree are not 

 the tree when properly put together, as to say water is not a part of the 

 tree nor developed by the tree. The gases that make water are in all things, 

 and by the chemical agency of vegetations they are evolved into the com- 

 pound called water. 



Dr. J. C. Brown, a conservative English writer and acknowledged author- 

 ity, is bolder in his conclusions than most of his peers. After fairly stating 

 both sides of the question as to whether forests do or do not promote rain- 

 fall, he thus strongly fortifies himself: 



"While moisture is necessary to make and keep forests, yet the forest in 

 turn conserves and reproduces moisture. These necessary and reciprocal 

 functions should not be arrayed against each other, any more than the 

 centrifugal and centripetal forces of nature, so as to invalidate the fact 

 that forests do retard the rainfall after precipitation and have a general 

 effect on the humidity of the atmosphere and soil." 



In further elucidation he suggestively maintains that moisture is aided 

 by the chemical change accompanying vegetation by the combination of 

 oxygen with hydrogen. He says, in his "Forests and Moisture," page 31: 

 "It is not unreasonable to suppose that all the ammonia taken up by the 

 plant may have been decomposed, the nitrogen combining with oxygen, set 

 free by the decomposition of the carbonic acid yielding material for the 

 woody structure and appearing as atmospheric air, and the hydrogen com- 

 bining with the oxygen and forming water." 



Dr. Brown but voices what is impliedly revealed. All chemists agree 

 that among the essential constituents of plant food for structure, when 

 refined and cooked, so to speak, are carbon and nitrogen, and that, 

 through the medium of the plants, the cooking process is performed under 

 the electric rays of the sun that wrest these elements from their crude alli- 

 ances, and when hydrogen and oxygen are thus set free, they combine and 

 form water. 



What is the oxidation of stones and metals down in the ground but a 

 slow burning of oxygen and hydrogen, forming water? From the food we 

 eat and the air we breathe, as with trees, is exhaled and cast out a watery sub- 

 stance, mixed more or less with carbonic acid gas, which when refined again, 

 as described, and exchanged, the animal and vegetable kingdoms are kept 

 in balance. What is it but a water-forming process? As to the amount of 



