Under the influence of the light and heat of the Sun, the entire population of this planet (about fifteen hundred millions) are renewed out of the crust of the Earth every few years, by breathing the air, drinking the water, feeding upon plants which take their constituents from the Earth, water and air; or by eating animals which have lived upon plants; and if that heat and light, or that supply of food and air, were to cease, all those human beings would die, and all the moral phenomena of man on this globe would terminate. Whilst man cannot exist without the support of inanimate nature and the operation of its laws, inanimate nature and its laws can exist without him. That also which is naturally ordained by Creative power to be dependent, cannot be essentially more important than that upon which it depends for its existence. The essential importance of man in relation to the Universe, exists only in his own imagination. These facts shew that the principles of science, and the physical and chemical properties of substances, lie at the very basis of man's existence and activity and it would therefore be incorrect to say that the physical system of the Universe is unimportant in comparison with the moral phenomena of mankind. That science conduces to humanity by preventing {150} and alleviating animal suffering has been already alluded to (p. 80-81). True humanity consists not in the abolition of experiments upon living creatures, but in the judicious employment of them. Instead of barbarously treating our suffering fellow creatures by indolently and ignorantly allowing causes of disease and pain to continually occur and take their course, it urgently enforces upon us the duty of extending our knowledge of physiology by means of new experiments, observations and study. It would be untruthful to say that experiments purposely made upon men and other animals do not yield new and valuable information;--Pharmacopoeias and Materia-Medicæs are full of descriptions of the properties of curative agents discovered by these and other scientific methods. Amongst the lesser virtues which have been greatly promoted by means of scientific research is that of cleanliness. The origin of soap was the discovery of the detergent properties of a boiled mixture of fat and alkali. The numerous inventions which have cheapened the most important soap-producing material, viz., washing soda, and those which have cheapened oil of vitriol, the chief substance consumed in making washing-soda, have all contributed to the cleanliness of mankind; and it has been stated that the degree of civilization of a nation might be ascertained by the amounts consumed of those substances.