Sound sleep is of the greatest importance. Most of the organs rest during sleep; the great brain in particular being completely at rest; but the disintoxicating glands are most active during sleep. This function should therefore be promoted by all means, and we shall devote a special chapter to sleep, its causation, and the treatment of insomnia. Let us, however, at once mention that sleep can best be encouraged by the use of a large, airy room, and going to bed early, say, at ten to half-past, and rising at five or half-past, when sleep has been undisturbed during the night. Seven hours’ sleep is the best; longer sleep, if over seven and one-half or eight hours, injurious, except for anæmic girls and women. Many people do very well with six hours’ sleep, but less than this will prove injurious in the long run. It is astonishing to note the large proportion of persons living to a very great age that were early risers; for which reason we may conclude that “early to bed and early to rise” is a valuable factor in the struggle against old age. We emphatically repeat, over and over again, the importance of fighting against our passions and cultivating the hygiene of the mind; this must be commenced in early childhood and continued through life; and the good qualities of the mind, which we will call the “positive” features of the mind, should be especially cultivated, such as kindness, good-heartedness, friendship, love, magnanimity, hope, modesty, liberality, generosity, frugality, and above all things, contentment with everything. On the other hand we may describe wickedness, unfriendliness, hatred, and jealousy as “negative” features of the mind, which should be smothered at their very inception in the child. The most successful way to fight the battle of life is to cultivate equanimity and follow the beautiful precepts of Hindu philosophy, which teach us never to hunger after honors and riches, but to be content with what comes in our way. It should be a lesson to us as to what to avoid when we take note of the manner in which so many American business men sacrifice their mind and health in an insatiable thirst for success and riches, and after attaining them, by a real battle with life, find their health so impaired that they reap no enjoyment from it. What is the use of a million when all that life holds dear is lost in the struggle to obtain it, and when, probably, our children will squander it, as do many sons of millionaires who have worked themselves to death. Rather be a living beggar than a dead millionaire!