In order always to be in a state of perfect health two things are necessary. Deny the power of disease over yourself. In the unyielding will is health. In the weak, vacillating, fearful mind is disease and death. At the same time always be in perfect magnetic trim with the physical laws of health. A knowledge of the latter and the ascension of a fearless mental attitude will open up hitherto unrecognised channels of physical and mental expression. Physiological researches have led sincere investigators to the inevitable conclusion that there is subtle, refined, dynamic substance, a reality that binds up the reorganization, causes growth, vitality and motion; repairs injuries; makes up losses; overcomes and cures diseases. Von Helment called it "Archeus"; Stahl called it "Anima;" Whytt called it the "sentiment principle;" Dr. Cullen called it "Caloric;" Dr. Darwin called it "Sensorial energy"; Rush called it "Occult cause;" and many other names such as "Vital Principle," "Living power," "Conservative Power," "Odic Force," etc., etc., have been given to it. We of India have recognised it and devised Yoga methods for controlling it; we call it Prana and only in India do you come across men who possess pranic control or control over universal energy.
There exists in your physical organism reserve stores of vital energy stored away for your use, particularly in that central ganglion of your vital battery known as the Solar Plexus and generally in the chain of ganglia or storage batteries along and up your spine and elsewhere in other nerve-centres. The solar plexus is also known as the Abdominal Brain and your brain depends and draws upon this vital centre for its energies. You will find after the prolonged concentration and brain-work that this part of your body—at the back of pit of stomach—becomes warm. Now when you engage in physical exercise, for instance, you must have noticed how at first you soon get tired and all done up. But if you wait a little and then start again, you will find how the sense of fatigue has quite passed away and you can run your body under full pressure for a very long time, and the more you exert yourself the greater and more powerful the surging up of your vital energy. With each new exertion you seem to acquire a fresh start. This has puzzled physiologists. You will find a parallel phenomenon in mental work. You may experience a sense of weariness and fatigue in some brain-work which demands close thinking and attention, but if you attack your work a little later after the first effort you will do your work a surprising degree of freshness, vigour, and enthusiasm far surpassing the original attempt. Again everyone can and does put forth universal energy under pressure of some urgent necessity, which will startle even himself. No matter who you are and what your physical condition, there is an enormous amount of power in your body that has never been drawn upon at all and impatiently waiting for up-call. We go on in ordinary dog trot pace, resting, limping, "taking care of our health," and then we think we are doing our best. Do not permit your mind to be self-hypnotised into a false sense of being "exhausted" and "old." Neither of them is a fact except in your thought of yourself. All your powers are lying dormant. All your latent energies are lying unused. Back of your conscious mentality are tremendous energies awaiting the pull of your will. When your brain conceives of being something unusually great, at least so it may appear from your view-point, do not question your strength but go ahead unhesitatingly, fearlessly and steadily. Assert your life-force. Feel that you are young, strong and healthy and fit. Live in mental consciousness of power and never think of weakness. Keep your grip and run right along. Nature is sure to honor your draft. Nature is sure to give you strength, energy and vim, in boundless measure. Just try this my friends, you, who write me of "there being a serious lack of vitality" in your system and hence your inability to grapple with the occult. No such thing. Fact is you lack courage and initiative, pluck and "go" and you are labouring under the hypnotism of weakening thoughts. Just change your thoughts, and your reserve forces will rush out into activity and you will be a changed man in no time.
HOW TO EXERCISE.
In exercising aim at rhythm of motion. Let your movements be easy, regular, rhythmic and graceful. Take an interest in your work. Do pay attention. Put Will-Power and Mind into your work. Think of all it means. Do not fatigue yourself unduly. After exercise towelling or a spray-bath is advisable. Wet your towel, pass it over your body, rubbing thoroughly. Raise the towel and repeat. After exercise and towelling, you should be in a splendid glow. Be sure to keep the windows open when exercising. Fresh air is an absolute necessity. Never mind about cold and so forth. Remember the Positive Denial will fill you with Power of Resistance. Say "Cold cannot affect my body" and believe what you say. You can face anything in this way and remain untouched.
BATHING AND LINEN.
The student should bathe daily, using plenty of water, rubbing and cleaning the body from top to toe. I myself bathe very early in the morning, in all seasons, in cold water. Cold water stimulates circulation and is a wonderful tonic internally and externally. Warm water is soothing and relaxing in its effect. If you can bathe in the flowing water of a river, so much the better. Swimming is a wonderful bracer, besides being an enjoyment in itself. There is Prana in water and your body extracts this Prana from air, water and food. I cannot give you instructions as to different forms of bathing, as this is not a "doctor" book. As far as possible bathe twice a day, mornings and evenings; if not, once in the morning, using the towel at other times. Bathing is not merely pouring water on body but cleansing it out and out with water rubbing and scrubbing with hands and towels. Aim at perfect cleanliness. Cleanliness is Godliness and Health is Holiness.
Then again while bathing if you let the water flow over your body and try to "appreciate the sensation" and dwell on the idea of Prana-absorption from water, you shall get double benefit.
About linen—Be neat, for God's sake. I have seen orthodox people who bathe twice and wash their hands hundreds of times in the day, but whose clothes are sticky with dirt, sweat and oil. Whatever else it may mean, Religion does not mean squalor, offensive odours in body and clothes and general neglect of external clean linen and dirt. The Yogi is a man of supreme REFINEMENT. Read that word and understand all it means. The clothes you wear in day-time should not be worn at night. Be clean internally as well externally. Be clean. Be clean. Be clean, within as well as without.
DRINKING WATER AND SWALLOWING AIR.
Your body needs a reasonable supply of water and air. Water is used by nature in different ways. Form the habit of drinking pure water from 5 to 8 tumblers a day. Drink slowly and form a mental image of Prana-absorption from the water.