This is particularly true of underwear, which should be light and porous, preferably linen next to the skin, which can be supplemented by extra woolen underwear placed over this to vary with the conditions of the temperature. Outings are essential to encourage free oxygenation through the lungs and the skin. Chill of surface is much more likely to follow exertion where too much or too heavy underwear is used, and the results are far more serious than if there is too little. If the skin be leaky, becoming readily moist on exertion, excessive precaution must be used lest secondary chill follow. If the underwear is made damp by exercise, it is important to change this as soon as possible and whenever it is produced. Above all the foot gear should be frequently changed to secure airing of these over-clothed members.
The most important specific recommendations I wish to offer for the postponement of the degenerative effects of age and for the recovery of so much of the normal vigor as is possible in each have to do with the forms and qualities of the exercises. As has been shown, the tendency of the tissues in advancing age is toward a steady and irretrievable hardening or stiffening or loss of elasticity, due to normal or abnormal increase in the connective tissue. The results of these changes are seen not only in the rigidity of the spinal column and ligaments, the skin, the muscle sheaths, the structures of the blood vessels, the connective tissue framework of the great organs, etc., which are obvious enough, but the really disastrous effects are those brought about by this xerosis upon the organs concerned in the processes of nutrition and of the special senses. This point I do not see brought out in any literature which has met my eye. Let me illustrate this. We have, as age creeps on, a loss in cellular activity in the functions of the special senses, well shown for example in dimness of vision, loss of hearing and slowness of cerebration. Much of this is inevitable and must continue. Some of this, however, can be delayed almost indefinitely. It will be observed that the tissues about the neck of an old person exhibit conspicuous loss of elasticity, so much that oftentimes dense rigidities are present, especially marked in the nuchal region.
I have been surprised and gratified to find that regulated movements of the neck and upper truncal muscles, employed for the purpose of accomplishing something else, resulted in a conspicuous improvement in hearing, in vision, in cerebration and, as a consequence of a betterment in cerebral circulation, also in sleep. Following this thought I have repeatedly been able to promise, and fulfil the promise, that an individual who had suffered impairment in these particulars should enjoy distinct improvement in the function of sense organs by employing regulated movements.
What is true of these structures is equally true of the abdominal viscera. A large proportion of the digestive disturbances, even of those in earlier middle life, are due to a relaxation in the supporting tissues
