No. 144.] 457 



trood contain 76 parts of carbon; 200 parts of dry hay 88 parts 

 oT carbon; 300 parts of dry straw contain 114 parts of carbon. 

 13ie question would now arise, where did the first vegetables ob- 

 tain their carbon from, and where humus. Numerous conditions 

 4re indispensable for the existence of plants^ because each variety 

 requires particular conditions, without which they cannot pos- 

 4bly be brought to maturity. The proper food for the perfection 

 o;f all the organs of a plant must assuredly contain all its ele^ 

 ments. A man, although he can live upon milk from infancy to 

 (lid age without other nourishment, would die if he were fed on 

 jelly, starch, sugar, or wheat bread constantly, to the total exclu- 

 lion of other food. 



Chemists have been at a loss to know the source from whence 

 oxygen is replaced ; when it is extracted in such large quantities, 

 gtill the quantity is always to be found precisely the same. One 

 hjindred parts of atmospheric air have neen found to contain 

 twenty-one parts of oxygen, in every part of the world. Jars 

 buried in Pompeii 1 ,700 or 1 ,800 years ago, were discovered to 

 contain the same proportions of oxygen, and yet the consumption 

 ts immcDse. For example, one man respires twenty-five cubio 

 feet of oxygen in every twenty-two hours; one half a ton of char- 

 coal consumes 32,166 cubic feet during its combustion, and every 

 14,000 of men extract annually by the luel they make use of, 

 1,102,000,000 of cubic feet. The consumption by combustion and 

 ajiimals, is very great. A calculation has been made showing 

 that a thousand million of men would render the air totally unfit 

 fcir respiration in a million years. 



Vitality is the power each organ has of always reproducing 

 itself, which it cannot do without a constant supply of the mat- 

 ters containing the constituent elements ; and besides these, both 

 plants and animals require inorganic substances, and among them 

 coumon salt, without which I believe men and animals would 

 Inevitably die. Plants must be supplied with metallic compounds 

 to do well. In the early period of the early history, plants did 

 not require any nourishment from the earthj being devoid of 

 foots. They consisted of huge palms, ferns, &c., as frequently 

 Ibuud in coal formatit^s, and possessed great leaves, whi^ 



