FORESTS OF THE NEW WORLD. 363 



vine-branch was found to have absorbed and 

 decomposed half the carbonic acid of this 

 portion of air in a very short time. These 

 plants, in decomposing the carbonic acid, had 

 appropriated its carbon and rejected the 

 oxygen. 



Before, however, this theory of the origin 

 of wood can be considered to be satisfactorily 

 confirmed, we should inquire whether the air 

 really contains sufficient carbonic acid to supply 

 the wants of the vegetable world. Humboldt 

 says, that in some of the forests of the New 

 World, monkeys might run a hundred miles 

 in a straight line upon the tops of the trees ! 

 The amazing mass of carbon contained in such 

 forests can therefore be scarcely represented 

 by the ordinary powers of numbers. Is it 

 possible that all this was derived from the air ? 

 Does, in fact, the atmosphere contain a sufficient 

 amount of this element to account for the sepa- 

 ration of so great a mass of it as exists in this 

 single instance, not to take into consideration 

 the entire vegetation of the rest of the globe? 

 The carbonic acid of the atmosphere has been 

 estimated at one-thousandth of its whole weight. 

 The entire weight of the atmosphere is known ; 

 and calculating upon it, it has been found that 

 the entire, weight of carbon contained at one 

 time in the atmosphere is about three thousand 

 and eighty-five billions of pounds. Calculations 



