... 28] food for the whale, through the marine insect, on which it feeds. After the abstraction of the oil from the whale, the nitrogen may, by the What is the source of the carbon of plants? What ... thousands of years. Still, at the decay of either of these, the carbon which they contain must be again resolved into carbonic acid. What are the coal-beds of Pennsylvania? 13] know enough of chemistry ... simply the union of the carbon of the blood with the oxygen of the air drawn into the lungs, and their breath, when thrown out, always contains carbonic acid. From this we see that the reproduction...