THE VOLATILE PART OF PLANTS. 31 
cium, magnesium, iron, and manganese, as well as oxygen, 
carbon, and nitrogen.* 
These fourteen bodies are elements, which means in 
chemical language, that they cannot be resolved into other 
substances. All the varieties of vegetable and animal 
matter are compounds,—are composed of and may be re- 
solved into these elements, 
The above fourteen elements being essential to the or- 
ganism of every plant and animal, it is of the highest im- 
portance to make a minute study of their properties, 
§ 2. 
ELEMENTS OF THE VOLATILE PART OF PLANTS. 
For the sake of convenience we shall first consider the 
elements which constitute thé destructible part of plants, 
Viz. : 
Carbon, Hydrogen, 
Oxygen, Sulphur, 
Nitrogen, Phosphorus. 
The elements which belong exclusively to the ash will 
be noticed in a subsequent chapter. 
Carbon, in the free state, is a solid. Weare familiar 
with it in several forms, as lamp:black, charcoal, anthracite 
coal, black-lead, and diamond. Notwithstanding the 
substances just named present great diversities of appear- 
ance and physical characters, they are identical in a cer- 
tain chemical sense, as by burning they all yield the same 
product, viz.: carbonic acid gas. 
That carbon constitutes a large part of plants is evident 
from the fact that it remains in a tolerably pure state after 
the incomplete burning of wood, as is illustrated in the 
preparation of charcoal. 
* Rarely, or to a slight extent, lithium, rubidium, i iodine, bromine, fluorine, 
barium, copper, zinc, and titanium. 
