THE CONSERVATION OF ENERGY.
CHAPTER I.
WHAT IS ENERGY?
Our Ignorance of Individuals.
1. Very often we know little or nothing of individuals, while we yet possess a definite knowledge of the laws which regulate communities.
The Registrar-General, for example, will tell us that the death-rate in London varies with the temperature in such a manner that a very low temperature is invariably accompanied by a very high death-rate. But if we ask him to select some one individual, and explain to us in what manner his death was caused by the low temperature, he will, most probably, be unable to do so.
Again, we may be quite sure that after a bad harvest there will be a large importation of wheat into the country, while, at the same time, we are quite ignorant
