largely, indeed, as to render physical sources of energy both indispensable and controlling in the vital economy.

Such considerations lead to inquiries as to the effects on the vital organism of the direct application of energy in the form of motion; whether functional activity may be reinforced and perfected thereby; under what circumstances, and to what extent; also, how far the consequences of functional failure, past and present, usually described as disease, may be corrected by this means alone. It will be observed, that the proposed therapeutic recourse differs from ordinary remedies in its essential independence of vitality as the initial source of help, on which other remedies of all kinds so very much depend.

The statements following are chiefly those of mechanical physiology, and are generally accepted in modern science. With these I may join facts derived from experience, arising from peculiar opportunities, facts hardly accessible to those whose experience is limited by the ordinary practice of medicine.

WHAT TRANSMITTED MOTION IS.

Transmitted motion is that communicated to the body or its parts through contact with some object in motion; this may be some instrument or machine, or the hand of another person-in either case, designed and adapted to produce certain effects by motion transmitted.

On account of the rapid exhaustion of the energy which any individual, however strong, is capable of exerting, those effects, producible by the hand of an operator, will not, for the present, be considered; attention being called only to those proceeding from more abundant and unfailing physical sources, as machines and instruments specially adapted by their construction to transmit power to the living organism.

The form of motion, capable of remedial effects, is that which in some way influences the ultimate constituent elements of matter, so as to change their destiny at will in some chosen direction. This power is necessarily vibrating or reciprocating; no other power is really communicable to the organism. Motion thus communicated is propagated in rapidly succeeding waves (1,000 or more per minute) through the substance of the body-its fluid, semi fluid and solid constituents; the force, as motion, gradually

diminishing as the distance from the point of its introduction

increases.

In the manner of transmission there may be considerable variety. The waves may be sent perpendicularly from the surface, or parallel with it: transversely or diagonally, with or without compression of the parts submitted to the action: the locality, direction, order, etc., securing variety of effects, from which the prescribing physician may select, according to the special indications of the case.

WHAT BECOMES OF THE ENERGY IMPARTED TO THE BODY IN THE FORM OF MOTION.

The amount of energy thus transmissible to the living body is evidently measurable, that is, it may be stated in some better known equivalents to facilitate comprehension of its amount; as we speak of steam engines as equivalent to certain horse power, and of horse power, as foot pounds.

This illustrates the positive nature of what is transmitted. A man may exert the whole power of his muscles in moving a weight; he may do the same, and in place of antagonizing gravi tation, may cause transposition, in a variety of ways, of the interior, invisible constituents of the organism of another person. An instrument conveying energy from some unlimited source may evidently do the same thing. In each case there is an equivalence of cause and effect; the latter, in the aggregate, is absolutely equal to the former. In the process, the causal energy has come to assume other forms-has taken new affiliations with matter. Thus, motion, introduced in the reciprocating form, will, in part, assume the direct form, as a pump sends a stream; in part, it appears as heat, as friction may produce ignition; while still another portion is spent in causing transposition of constituent atoms, or chemical effects; as sudden impact may produce explosion of some mixtures, while stirring will cause precipitation in others-evidences of chemical effects of motion, that is, motion transformed to chemical affinity.

That force or energy, under the circumstances stated, is not lost, or in any degree diminished, is the dictate of modern science. Force is never lost; it only changes its form by change of circumstances; its elusiveness is evidence of change, not loss. We may still trace energy imparted, as above stated, through numerous

phases and fields of action; we may even detect it in the performance of most necessary physiological work, without which the powers manifested by the vital system are utterly impossible. In so far as we shall find energy, force, or power, thus transmitted, to supplement those deficiencies of organized energy which we characterize as disease, it falls into the category of remedies, and we are compelled to regard it as remedial. Beginning with effects purely physical, we may easily trace a portion of these equivalents of motion up to the very threshold of vitality.

DISPLACEMENT.

The bulk of the vital system consists of fluid; blood inside the circulatory vessels, and interstitial fluid exterior to the vessels. This mass of watery fluid, though pervading and pervaded by vitality, is non-vital, at least so far as to be strictly amenable to physical control. The blood transports nutrition; the interstitial fluids carry nutritive matter, and participate in nutritive actions and changes.

An impinging force displaces fluids; those contained in canals or conduits, as blood vessels, are urged forward in the direction allowed by their valves. Every repetition of the impinging force increases the effect. Mechanical obstacles, if such exist in the blood vessels, are necessarily removed, broken up, or urged out of the way; the outflow of blood, both to and from the nutritive capillaries, is perfected. This effect is soon indicated in the quality of the organic effort directed to the same end; the pulse becomes slower and fuller. The motions of the nutritive fluid are entirely obedient to the same control. Increased nutrition of tissues, superinduced by the fresh supplies of blood, laden with oxygen, causes motion of the fluids in the direction of the scene of activity; while the onflowing venous currents recall mechanically, within the walls of the veins, such spent matters as are destined to be excluded. Hence, the mechanism of the circulation of the blood and interstitial fluids is, by exterior motion, set and kept in action in all the minute details necessary to nutrition and the support of vitality, but without the least vital expenditure; and, although entirely in harmony with the ordinary causes, yet quite independent of them. An auxiliary cause has practically come in to carry forward defective action to the perfected stage.

It will be apparent that the effects just described are no other, in kind and degree, than those occurring in health, when the ordinary and spontaneous action of the muscles secures the same effects. The contracting muscles press upon both the blood in its channels and the interstitial nutritive fluids, and produce the same effect as may be produced by mechanical impingement of exterior force, contributed by some instrument adapted to this purpose. The fluids which enter into the composition of the body have not the least power of self motion, but depend on impulses generated within or received from without the system for whatever change of place they suffer. The physiological consequences are quite the same, from whatever source the power which produces them may be derived.

FRICTION-HEAT-CHEMICAL CHANGE.

Fluids in motion, especially those whose fluidity is imperfect, and motion of fluids in contact with solids, causes heat; or, to speak in the language of science, converts motion into heat. Rumford experimentally caused water to boil in boring submerged cannon, and thus were obtained data for finding the equivalents of the two forms of energy. The facility of the change of motion to heat appears to be in the ratio of adhesiveness or friction.

The physical nature of the components of the human body, soft, semi-fluid, adhesive, and moderate pressure, conjoin to favor the transformation of motion to heat. When, therefore, reciprocating or vibrating motion is transmitted through sections of the living body, the temperature of the whole, beginning with the part submitted to action, quickly rises. The circulation of the blood appears to diffuse the increased temperature throughout the body, and increased transpiration soon gives evidence that a surplus is being produced, and is disposed of through the whole surface.

All organized beings are developed only at fixed temperatures, and the progressive development depends on the maintenance of such temperature. The fact that heat promoting remedies are favorites with physicians of all classes, is strong evidence of the importance attached by them to the heat making function. The heat of living beings comes from two sources. One source is the motion pervading all living parts, which, whether derived from vital or extra vital sources, is in part transformed to heat.

Another is the heat set at liberty by the abundant chemical

change that is the concomitant of all life. These two causes of the bodily temperature are intimately connected; for motion is not only changed to heat, but incites oxidation also. Heat is, therefore, a most important remedy.

One of the first indications of disease is irregularity of the heat making functions. Although there may be actual excess of temperature, its production is really, in every case, diminished; the excess is owing to its retention with the imperfectly oxidized matters, associated with which heat should be eliminated.

Chemical changes in the vital system depend on conditions quite similar to heat. Composition and decomposition of the ever changing constituents of the body, vital and non-vital, are possible only by contact of the atoms among which such changes occur; and contact is the necessary result of motion. Motion is, therefore, absolutely essential for all chemical actions. Friction, or contact with some degree of force, naturally affords a higher and more perfected result than feeble contact; the constituents of the body following the same law as matters exterior to it. Sluggish chemical action and imperfect vital results are, therefore, by the assistance of motion, carried forward to those perfect results that are compatible with vitality and health. And, in the same way as before indicated, exterior sources of motion bring about effects physiologically indistinguishable from those generated from the usual interior sources of motion. In other words, motion is a remedy, so far as relates to organic vital chemistry.

This principle is specially exemplified in that indispensable accompaniment of all animal life—the oxidizing process. Imperfect health betokens, in the same degree, imperfect oxidation and imperfect removal of the waste products of vital action and expenditure. The oxidizing process within the vital system is peculiar in being always progressive, or proceeding in stages, instead of being a single process, as is usual in the inorganic world.

The difference between health and disease is probably commensurate with these stages of oxidation. Not that any actual form of disease is predicable on such data, for interminable secondary effects, in which vitality plays a more or less prominent part; in which, also, inherent constitutional tendencies and considerations largely enter, conflict with the possibility of definite conclusions in