the phenomena of light and electricity abundantly prove. While so tenuous that Astronomy has been taxed to prove that it exerts an appreciable resistance upon the least of the celestial bodies, its elasticity is such that it transmits a compression with a well nigh infinite velocity.114 On the one hand, Thomson has determined its inferior limit, and finds that a cubic mile of it would weigh only one thousand-millionth of a pound;115 on the other, Herschel has calculated that, if an amount of it equal in weight to a cubic inch of air be enclosed in a cubic inch of space, its reaction outward would be upward of seventeen billions of pounds.116 Instead of being represented as is our air, by the pressure of a homogeneous atmosphere five miles in height, such a pressure would represent just such a homogeneous atmosphere five and a half billions of miles high, or about one-third the distance to the nearest fixed star! In Herschel's own words: "Do what we will, adopt what hypotheses we please, there is no escape in dealing with the phenomena of light, from these gigantic numbers; or from the conception of enormous physical force in perpetual exertion at every point through all the immensity of space.'

"117

Now, as Preston has suggested,118 if we regard this ether as a gas, defined by the kinetic theory that its molecules move in straight lines, but with an enormous length of free path, it is obvious that this ether may be clearly conceived of as the source of all the motions of ordinary matter. It is an enormous storehouse of energy, which is continually passing to and from ordinary matter, precisely as we know it to do in the case of radiant transmission. When potential energy becomes kinetic, the ether loses and the matter gains motion. When kinetic energy becomes potential, the lost energy of the matter is the motion gained by the ether. Before so simple a conception as this, both potential energy and action at a distance are easily given up. All energy is kinetic energy, the energy of motion. Giving now to the ether its storehouse of tremendous power, and giving to it the ability to transfer this power to ordinary matter upon opportunity, and we have an environment compared with which the strongest steel is but the breath of the summer air. In presence of such an energy it is that we live and move. In the midst of such tremendous power do we act. Is it a wonder that out of such a reservoir the power by which we live should irresistibly rush into the organism and develop the transmuted energy which we recognize in the phe

nomena of life? Truly, as Spinoza has put it, "Those who fondly think they act with free will, dream with their eyes open."

"119

Such now are some of the facts and the theories to be found in the science of to-day concerning the phenomena of life. Physiologically considered, life has no mysterious passages, no sacred precincts into which the unhallowed foot of science may not enter. Research has steadily diminished day by day the phenomena supposed vital. Physiology is daily assuming more and more the character of an applied science. Every action performed by the living body is sooner or later, apparently, to be pronounced chemical or physical. And when the last vestige of the vital principle as an independent entity shall disappear from the terminology of science, the word "Life," if it remain at all, will remain only to signify, as a collective term, the sum of the phenomena exhibited by an active organized or organic being.

I cannot close without speaking a single word in favor of a vigorous development in this country of physiological research. What has already been done among us has been well done. I have said with diffidence what I have said in this address, because I see around me those who have made these subjects the study of their lives, and who are far more competent to discuss them than I am. But the laborers in the field are all too few, and the reasons therefor are not far to seek. One of these undoubtedly is the high scientific attainment necessary to a successful prosecution of this kind of investigation. The physiological student must be a physicist, a chemist, an anatomist and a physiologist all at once. Again, the course of instruction of those who might fairly be expected to enter upon this work, the medical students of the country, is directed toward making them practitioners rather than investigators. In the third place the importance of physiological studies in connection with zoological research is only beginning in this country to receive the share of attention it deserves. I well remember the gratification I experienced in 1873 upon receiving a letter from Professor Louis Agassiz, announcing his intention to have lectures at Penikese upon physiological chemistry; a new departure for those times. In this view of the case it seems very appropriate that a new subsection of this Association should be just now in process of formation. We welcome warmly the body of men who form it and we predict that from the new subsection of Anatomy and Physiology most valuable contributions will be received for our proceedings.

It is a beautiful conception of science which regards the energy which is manifested on the earth as having its origin in the sun. Pulsating awhile in the ether-molecules which fill the intervening space, this motion reaches our earth and communicates its tremor to the molecules of its matter. Instantly all starts into life. The winds move, the waters rise and fall, the lightnings flash and the thunders roll, all as subdivisions of this received power. The muscle of the fleeing animal transforms it in escaping from the hunter who seeks to use it for the purpose of his destruction. The wave that runs along that tiny nerve-thread to apprise us of danger transmutes it, and the return pulse that removes us from its presence is a portion of it. The groan of the weary, the shriek of the tortured, the voicéd agony of the babeless mother, all borrow their significance from the same source. The magnificence of the work of a Leonardo da Vinci or a Michael Angelo; the divine creations of a Beethoven or of a Mozart; the immortal Principia of a Newton and the Méchanique Celeste of a Laplace,―all had their existence at some point of time in oscillations of ether in the intersolar space. But all this energy is only a transitory possession. As the sunlight gilds the mountain top and then glances off again into space, so this energy touches upon and beautifies our earth and then speeds on its way. What other worlds it reaches and vivifies, we may never know. Beyond the veil of the seen, science may not penetrate. But religion, more hopeful, seeks there for the new heavens and the new earth, wherein shall be solved the problems of a higher life.

NOTES.

1 H. Bence Jones, Croonian Lectures on Matter and Force, London, 1868.

2 Herbert Spencer, Principles of Biology, New York, 1871, I, 60.

3 Küss, Lectures on Physiology, Edited by Duval and Translated by Amory, Boston, 1875, 2.

4"Among the phenomena of life those which are intelligible to us are precisely of the physical or mechanical order."— Marey, Animal Mechanism, New York, 1874, 7. "All action of which we are immediately cognizant is but the result of the operation of the solar heat upon and through independent and correlative existences." "Conservation of energy makes more and more doubtful the existence of a vital principle, and tends to bring the phenomena of living bodies more and more within the domain of pure physical necessity."-Acland, Medicine in Modern Times, London, 1869, 23.

5"An animal can no more generate an amount of force capable of moving a grain of sand, than a stone can fall upwards or a locomotive draw a train without fuel.

Frankland, Phil. Mag. IV, xxxii, 182; Proc. Roy. Inst., June 8, 1866; Am. J. Sci., II, xlii, 333, Nov., 1806.

* Haughton, Medicine in Modern Times, 107. Lavoisier, Ib., 113; also Phys. Chem. Schriften, 1785, Bd. III.

* Bischoff and Voit, Die Gesetze der Ernährung des Fleischfressers, Munich, 1860. "They found that the amount of urea eliminated was not in proportion to the exercise of force, but the amount of carbonic acid was so."-Sci. Conf., 174. Lawes and Gilbert, South Kensington Science Conferences, London, 1876, Biology, 173, 174, "I believe it is now accepted that the elimination of urea is no measure of the muscular force ex erted within the body. Haughton, loc. cit., 108, "No greater mistake is possible in Physiology than to suppose that the products of the changes in the blood, by which mechanical or intellectual work is done, are themselves merely the result of the waste of the organs whether muscles or brain, on the exercise of which that work depends." Theodor, Zeitschr. f. Biol., xiv, 51-56; J. Chem. Soc., xxxvi, 74. Voit, Ib., 57-160; Ib., 75. Also, Untersuchungen über den Einfluss des Kochsalzes, des Kaffees, und der Muskelbewegungen auf den Stoffwechsel, Munich, 1860. Fick and Wislicenus, Phil. Mag., IV, xxxi, 485. Smith, E., Phil. Trans., 1859, 709; 1851, 747. Parkes, Proc. Roy. Soc., xv, 339; xvi, 44. Noyes, Am. J. Med. Sci., Oct., 1867. M. Foster, Textbook of Physiology, 3d ed., London, 1880, 471.

Haughton, loc. cit., 120.

* Haughton, Animal Mechanics, London, 1873. On Law of Fatigue, see Proc. Roy. Soc., 1879, 1880; Nature, xxii, 128, 1880; Am. J. Sci., III, xx, 147.

10 Du Bois Reymond, Untersuch. ü. thierische Elektricität, 1848-1830. Marey, loc. cit. 22, 50. Radcliffe, Dynamics of Nerve and Muscle, London, 1871, 26. Hermann, Nature, xix, 561. Haughton, Animal Mechanics, 5. Maudsley, Physiology and Pathology of Mind, 2d ed., London, 1868, 42. Voit and Theodor, J. Chem. Soc., xxxvi, 951. The conclusions are: 1st, the muscles are the centre of the formation of CO2, in health 403 grams being excreted, and in a paralytic 250 grams. 2d, lowering of the temperature from 14.3° to 4.4° increases the CO2 from 155.0 to 210.7 grams. 3d, the urea was not increased, showing that the non-nitrogenous matter was burned. Foster, op. cit., 66, 116, et seq. Gamgee, Physiol. Chemistry Anim. Body, London, 1880, 345 et seq.

159.

11 Matteucci, Physical Phenomena of Living Beings, London, 1817, 205, 216, 331. 12 E. J. Marey, loc. cit., 53; Nature, xix, 295, 320; C. R., lxxxiv, 190, 354, 1877.

13 Students' Text-Book of Electricity, Noad, 4th ed., edited by Preece, London, 1879,

14 Donders and Buys Ballot, Over de Elasticiteit der Spiren, Utrecht, 1863, 47. Quoted in Animal Mechanics, 2.

15 Radcliffe, C. B., Dynamics of Nerve and Muscle, London, 1871, 29. Matteucci, loc. cit., 216, "The analogies between muscular contraction and the discharge of the torpedo are complete; what destroys, augments and modifies the one, acts equally upon the other." Marey, " 1st, the rapidity of the nervous agent in the electrical nerves of the torpedo seems evidently to be the same as that of the nervous agent producing motion in the frog. 2d, the phenomenon called by Helmholtz lost time exists also in the electric apparatus of the torpedo and lasts about the same time as in the muscle. 3d, the discharge of the torpedo is not instantaneous but is prolonged about 0.14 of a second; which is in a remarkable degree equal to the duration of the shock of the frog's muscle." Animal Mechanism, 57.

18 Wollaston, Phil. Trans., 1809.-Haughton, Anim. Mechanics, 16. "It resembles most nearly the deep hum produced by the blowing fan of a large foundry." It is obtained by gently inserting the extremity of the finger into the ear, bringing at the same time the muscles of the hand and forearm into strong contraction. Brunton places the ball of the strongly contracted thumb against the ear. Sci. Conf., 193.

17 Weber, Muskelbewegung, Wagner's Handwörterbuch. Minot, C. S., Jour. Anat. Physiol., xii, 297, 1878. Lauder Brunton, Sci. Conf., Biology, 192-1. Marey, Animal Mechanism, 47.

18 Marey, Compte Rendu des Travaux du Laboratoire de M. Marcy, Paris, 1877, iii. "1st, a torpedo's discharge is not a continuous current. It is formed of a series of successive waves, added one upon another. 2d, each electric wave presents a phase

of suddenly increasing intensity followed by a phase of gradually decreasing intensity, 3d, currents induced by a torpedo discharge are all produced at the beginning of each wave. 4th, there are currents induced on the completion of a circuit, the inverse of the inducing currents, as is shown by the electrometer. 5th, the discharge of the torpedo is analogous to muscular tetanus; every electric wave in the discharge corresponds to a muscular shock." Thus we see that a muscle-shock, like an electric discharge, is produced by a single excitation, the delay being the same, about seven hundredths of a second. The wave, like the shock, increases more abruptly than it decreases, alike in muscle and electric organ. The same agents modify the wave and shock similarly. Heat renders both more energetic up to a certain point, from which both disappear. Cold diminishes both and they both cease at zero. In both, the waves and the shocks run into each other in the same manner. Both suffer from fatigue alike and both are alike affected by poisons. "Does the fact that a voluntary discharge of the torpedo is a complex act not prove that the voluntary contraction of the muscles is also a complex act? Very certainly the comparison of the voluntary contraction of the muscles with the tetanic phenomena produced by electricity, or strychnine, the existence of a muscular sound during the contraction, the quivering or dissociation of the shocks which are produced under the influence of cold,—all these seem arguments in favor of the theory which considers muscular contraction as the result of very frequent shocks; but the complexity of the voluntary discharge of the torpedo, the manner in which the waves composing it succeed each other and are added together, forms a very important confirmation of the numerous presumptions already made." Abstract by Francois Franck, Nature, xix, 295, 320.

19 Feddersen, Pogg. Ann., ciii, 69. O. N. Rood, Am. J. Sci., II, xlviii, 153, 1869. A. M. Mayer, Ib., III, viii, 136, 1874. The electric spark in air, and probably also the discharge through conductors, is intermittent and consists of a great number of oscil. latory movements. In a private communication from Dr. T. A. Edison, he states that muscular tetanus can be produced by rapid vibrations of a purely mechanical character; the effect closely resembling that which results from the secondary current of an induction coil.

20 Matteucci, loc. cit., 195, 252. M. Foster, Physiology, 44-46. "When a frog is poisoned with urari, the nerves may be subjected to the strongest stimuli without causing any contractions in the muscles to which they are distributed; yet even ordinary stimuli applied directly to the muscle readily cause contractions." "The activity of contractile protoplasm is in no way essentially dependent on the presence of nervous elements."

21 Matteucci, loc. cit., 200. "The origin of this current resides in the electric conditions which are produced by the chemical actions of the nutrition of the muscle." Marey, loc. cit., 55. "As to the origin of the electric force, we think no one can now see anything in it but the result of chemical actions produced in the interior of the apparatus."

22 Prof. Sir Wm. Thomson, Electrostatics and Magnetism, 1872, 317. Fleeming Jenkin, Electricity and Magnetism. 44. "If two metals (as copper and zine) be plunged in water, the copper, the zinc, and the water forming a galvanic cell, all remain at one potential and no charge of electricity is observed on any part of the system."

23 Peclet, Ann. Chim. Phys., III, ii, 233. Kohlrausch, Pogg. Ann., lxxxviii, 465; lxxii, 353; lxxxii, 1. Buff, Ann. Chem. Pharm., xlii, 5; xlv, 137. Becquerel, Ann. Chim. Phys., xxv, 405; C. R., xxii, 677. Hankel, Pogg. Ann., cxxvi, 286. Gerland, Ib., cxxxiii, 513. Du Moncel, C. R., xc, 964; La Lumière Electrique, ii, 357, 1880. Pellat, C. R. xc, 990. Ayrton and Perry, Proc. Roy. Soc., 1878-9; Phil. Trans., 1879; Nature, xix, 498, 1879. Everett, Units and Physical Constants, 146-150, 1879. Gore, Nature, xxii, 21. Edelmann, Rep. f. Exp. Physik., xvi, 464, 1880. B. O. Peirce, jr., Inaug. Diss., Leipzig, 1879.

24 L. Cumming, Theory of Electricity, London, 1876, 120, et seq.

25 Peltier, Ann. Chim. Phys., Ivi, 371, 1834. Tyndall, Phil. Mag., IV, iv, 419. Lenz, Pogg. Ann., xliv, 342. Bouty, C. R., xc, 917, 987, 1880.

26 Prof. Sir Wm. Thomson, Phil. Mag., IV, iii, 529, 1852; viii, 62-69; Phil. Trans., iii, 661, 1856. Jenkin, Electricity and Magnetism, 187.