SCIENCE. 



In regard to the prize essay, we would advise Mr. 

 Warner to postpone the time of entry until January 

 the i st next, which will give a reasonable time for 

 some creditable work to be done. We would also 

 propose- that the judges be named immediately. 

 Professor Swift says in his letter, "as to who will 

 appoint the judges I am as ignorant as are you." 

 Who does know ? Surely Mr. Warner will not pro- 

 pose to decide this matter. 



In making these remarks we are far from desiring 

 to disparage the value of such prizes as those offered 

 by Mr. Warner. We understand that Mr. E. E. 

 Barnard, who secured the last prize, is a young man 

 under twenty-five years of age, and a self-taught 

 astronomer. Under very discouraging financial cir- 

 cumstances he provided himself with a good five-inch 

 telescope, with which he has done excellent work. 

 His Warner prize will be turned to good account, as 

 he writes to inform us that the $200 will enable him 

 to purchase a plot of ground on which to build a 

 house for his family ; we need not add that an observ- 

 atory will be a leading feature in Mr. Barnard's new 

 house. 



We feel a pleasure in showing the practical good 

 Mr. Warner is doing by providing these scientific 

 prizes, and we trust he may continue them during the 

 following year. Our criticism is of a perfectly friendly 

 character and made with some regret. We have re- 

 ceived letters from subscribers confirming our view of 

 the case, which will remain unpublished, as we desire 

 to close the discussion. 



ON THE DISCOVERIES OF THE PAST HALF- 

 CENTURY RELATING TO ANIMAL MOTION. 

 By J. Burdon-Sanderson, M. D., L.L.D., F.R.S. 



[Concluded from Page 486.] 



The living muscle of a frog is placed in a closed cham- 

 ber, which is vacuous — i. e. contains only aqueous vapor. 

 The chamber is so arranged that the muscle can be 

 made to contract as often as necessary. At the end of a 

 certain period it is found that the chamber now con- 

 tains carbonic acid gas in quantity corresponding to the 

 number of contractions the muscle has performed. The 

 water which it has also given off cannot of course be 

 estimated. Where do these two products come from ? 

 The answer is plain. The muscle has been living all the 

 time, for it has been doing work, and (as we shall see im- 

 mediately) producing heat. What has it been living on ? 

 Evidently on stored material. If so, of what nature? If 

 we look for the answer to the muscle, we shall find that 

 it contains both proteid and sugar-producing material, 

 but which is expended in contraction we are not informed. 

 There is, however, a way out of the difficulty. We have 

 seen that the only chemical products which are given off 

 during contraction are carbonic acid gas and water. It 

 is clear, therefore, that the material on which it feeds 

 must be something which yields, when oxidized, these 

 products, and these only. The materials which are stored 

 in muscle are oxygen and sugar, or something resembling 

 it in chemical composition. 



1 Ludwig't first impcrtant research on this subject was published in 1881. 



And now we come to the last point I have to bring be- 

 fore you in connection with this part of my subject. I 

 have assumed up to this moment that heat is always pro- 

 duced when a muscle does work. Most people will be 

 ready to admit as evidence of this, the familiar fact that 

 we warm ourselves by exertion. This is in reality no 

 proof at all. 



The proof is obtained when, a muscle being set to con- 

 tract, it is observed that at each contraction it becomes 

 warmer. In such an experiment, if the heat capacity of 

 muscle is known, the weight of the particular muscle, 

 and the increase of temperature, we have the quantity of 

 heat produced. 



If you determine these data in respect of a series of 

 contractions, arranging the experiments so that the work 

 done in each contraction is measured, and immediately 

 thereupon reconverted into heat, the result gives you the 

 total product of the oxidation process of heat. 



If you repeat the same experiment in -such a way that 

 the work done in each contraction is not so reconverted, 

 the result is less bv the quantity of heat corresponding to 

 the work done. The results of these two experiments 

 have been found by Prof. Fick to cover each other very 

 exactly. I have stated them in a table 1 in which we have 

 the realization as regards a single muscle of the following 

 forecast of Mayer's as regards the whole animal organ- 

 ism. " Convert into heat," he said, " by friction or 

 otherwise, the mechanical product yielded by an animal 

 in a given time, add thereto the heat produced in the 

 body directly during the same period, and you will have 

 the total quantity of heat which corresponds to the 

 chemical processes." We have seen that this is real- 

 izable as regards muscle, but it is not even yet within 

 reach of experimental verification as regards the whole 

 animal. 



I now proceed abruptly (for the time at our disposal 

 does not admit of our spending it on transitions) to the 

 consideration of the other great question concerning 

 vital motion, namely, the question how the actions of the 

 muscles of an animal are so regulated and coordinated 

 as to determine the combined movements, whether 

 rhythmical or voluntary, of the whole body. 



As every one knows who has read the " Lay Ser- 

 mons," the nature and meaning of these often uninten- 

 tional but always adapted motions, which constitute so 

 large a part of our bodily activity, were understood by 

 Descartes early in the seventeenth century. Without 

 saying anything as to his direct influence on his contem- 

 poraries and successors, there can be no doubt that the 

 appearance of Descartes was coincident with a great 

 epoch — an epoch of great men and great achievements 

 in the acquirement of man's intellectual mastery over na- 

 ture. When he interpreted the unconscious closing of 

 the eyelids on the approach of external objects, the acts 

 of coughing, sneezing, and the like as mechanical and 

 reflected processes, he neither knew in what part of the 

 nervous system the mechanisms concerned were situ- 

 ated, nor how they acted. 2 It was not until a hundred 



1 Relation of Prodict and Process in Muscle. 



(Result of one of Fick's Experiments.) 



Mechanical product 6670 grammemillimetres. 



Its heat value 15-6 milligrammeunits. 



Heat produced 30.0 



Total product reckoned as heat- 54.6 



a Descartes' scheme of the central nervous mechanism comprised all the 

 parts which we now regard as essential to " reflex-action." Sensory 

 nerves were represented by threads (filets) which connected all parts of 

 the body to the brain ('* (Euvres." par V. Cousin, vol. iv., p. 359) ; motor 

 nerves by tubes which extended from the brain to the muscles ; " motor 

 centres" by "poies" which were arranged on the internal surface of the 

 ventricular cavity of the brain, and guarded the entrances to the motor 

 tubes. This cavity was supposed to be kept constantly charged with 

 "animal spirits" furnished to it from the heart by arteries especially des- 

 tined for the purpose. Any " incitation " of the surface of the body by an 

 external object which affects the organs of sense does so, according to 

 Descartes, by producing a motion at the incited part. This is communi- 

 cated to the pore by the thread and causes it to open, the consequence of 

 which is that the " animal spirit " contained in the ventricular cavity 

 enters the tube and is conveyed by it to the various muscles with which 

 it is connected, so as to produce the appropriate motions. The whole system, 



