Every new item of nature's news that breaks upon the consciousness increases capacity for pleasure for all time. He who meets nature with enlightened senses is rewarded every day of his life for the pains taken in delightful study by way of preparation. A landscape is infinitely enhanced to him who has pursued the science of color with some diligence. The sounds of the forest speak tenderly to all; but he who knows the secrets of melody and harmony, and the limits of human skill in music, has worlds of delight in the forest that others may not enter. And so has the swain whose childhood was spent among the voices of the trees. The sense of smell has a thousand raptures for the man whose nose has lived up to its possibilities. To look upon all nature broadly with the familiarity which comes only from long acquaintance and scientific investigation of her various aspects is the highest type of living. While this is not possible to all, yet, much of it may be experienced by every one who has the desire and follows it. The leading facts of all the sciences are open to all who care to know them. The beauties and mysteries of the world are constantly inviting us. And the rapid developments of knowledge in all directions give us all the exciting motives one can desire. Looking out over the face of the world, we note that there are two sorts of material to be considered. One is alive or was produced by the action of life, and the other is material which has never known a want. We are drawn most to that which has pulsed with sap or blood--that which has made a struggle of some sort. All things that live are made up chemically principally of four of the elements of the universe which are best adapted by their characteristics for the purposes of life. Three are gases, oxygen, hydrogen, and nitrogen; one is a solid, carbon. All these have what is technically known as affinities of narrow range and low intensity except oxygen. Oxygen is greedy to attack almost everything, the others unite but sparingly and feebly. From these elements, life chooses combinations that are easily changed in form and light enough to stand up from the earth, to swim in the waters, and even to fly in the atmosphere. So gaseous and quick to change are the things of life that life itself has the reputation of being fleeting. Development is a change in the arrangement of parts, and function is a transformation of motion. These four elements, three gaseous and one solid, three very exclusive and one very free in choosing all sorts of associates, have been the means whereby life has been possible upon the earth. Their characters have provided for what are known as differentiation and integration.