ments to the tissues. It is the expression or result of the process of local feeding. If a part is active it will be heated. When the feet are left bare the complex muscular apparatus of the extremity, which in a stiff shoe scarcely works, is called into vigorous action, the arch of the foot plays with every step, and each toe performs its share in the act of progression. This promotes growth and calls for nutrition, whereby the heat is maintained; whereas if it be simply packed away as a useless piece of organism, no amount of external heat will warm it. Work is the cause and counterpart of heat throughout the body.

The same principle applies to the head. No amount of external cooling will reduce the temperature, no drawing away of the blood by artificial. expedients will permanently relieve the sense or obviate the fact of heat if the organ within the cranium is excessively or morbidly active. The brain is a peculiarly delicate and complicated organ, requiring more prompt and constant nutrition than any other part of the body, because the constituent elements of its tissue change more rapidly than those of any other in proportion to the amount of exercise. Moreover, the brain is always acting during consciousness, and even in sleep it is seldom wholly at rest, as we know from the occurrence of

dreams. The faculty of nutrition is highly developed in the organ or it could not so continuously, and ont he whole healthily, discharge its functions, even when other parts of the body, or the system as a whole, are suffering from disease. When the head is heated there is nearly always a local cause for it, and the remedy must be addressed to the seat of the malady. The temporary expedient of "drawing away the blood" by applying heat to the extremities is useful as far as it goes, and may suffice to enable the organ to rid itself by the contraction of its blood-vessels from a surplus charge of this fluid, but in the absence of special causes the reason of the "heat of head" is undue exercise or disturbance of nutrition in the brain itself. Perhaps the seat of the over-work and consequent heating may have been limited to a particular part of the head; for example, the apparatus of sight, or hearing, as when the head becomes heated by reading too long or in a strong light. The point to understand is that when the head is physically hot it is the seat of too much or disorderly nutrition, and either the amount of brain or sense-power exercised must be reduced or the mode of action changed, and the particular part of the apparatus of perception or thought which has been too severely taxed relieved.

From these general observations—recapitulating a few only of the more notable facts in relation to heat and heat production—we may draw the following conclusions. First, the heat of the body depends on its own condition and functions rather than on the temperature of the objects by which it is surrounded. There is a wonderful power of selfpreservation and adaptation to external needs provided in the constitution of man, and his chief aim should be to aid instead of hindering the exercise of this beneficent faculty. Second, external temperature ought to be treated rather as an enemy than a friend; and the body should be so trained as to resist its variations. If we rely on the aid of the heat without to help the heat within, we must expect to be chilly when the weather is cold, and responsive to all its variations. The body which seems out of health in cold weather is essentially unhealthy: it is deficient in the power of heat-generation, and unless it can be shown that some accidental waste is going on which depresses the vital powers, and so accounts for this weakness of function, it may be assumed that either the heart is feeble or diseased, the blood-vessels are out of condition, or there is a defect somewhere in the apparatus of nutrition. The true condition of health is that in which the

temperature of the body as a whole and of its several parts is not disturbed by surroundings either of heat or cold. Third, the preservation of a natural and healthy temperature is mainly to be secured by the maintenance of a regular and well distributed circulation of blood charged with the materials of nutrition.

The first condition of a free and continuous flow of blood is a healthy heart, not hampered by irritants, mental or physical. Sudden grief or fright produces cold by arresting the circulation, and the flow may be permanently retarded by anxiety. The mind has a wondrously direct influence on the heart and blood-vessels-on the latter through the nerves, which increase or reduce the calibre of the minute arteries, as in blushing or blanching at a thought. Instead of loading the body with clothes, the "chilly" should search out the physical cause of their coldness. The blood must not only circulate freely; it must be rich in nourishing materials, and not charged with poison. An excess of any one element may destroy the value of the whole. It is too much the habit of valetudinarians and unhealthy people of all kinds, to charge the blood with substances supposed to be "heating" or "cooling" as they think the system requires them. This is a mistake. The body does not need to be pam

pered with cordials, or refrigerated with cunningly devised potions. If it is well nourished it will be healthy.

HABIT.

It is surprising to find, on close scrutiny, how large a proportion of the acts we perform, seemingly at the bidding and under the control of the will, are in truth performed unconsciously. Walking, running, leaping, lifting and carrying burdens-in fact, most of the actions in which the muscular system is engaged-are accomplished without the cognisance of details. The end only is perceived; the will is engrossed with the result, and ignores the steps by which it is reached. We set out to walk on a particular road to a certain place; the feet and legs are set in motion and we continue walking, while the whole attention is absorbed with matters of thought, no concern being bestowed on the management of the limbs unless unusual or unexpected sensations attract the notice of the mind. We carry a book or a parcel, and hold it, though its possession may be forgotten. In short, there is