NOVKMBEU -^3, 1S83.| 



SCIENCE. 



671) 



of sensibility and those of movement; to determine 

 the courses of the two kinds of nerves in llie various 

 parts of the body. We know how excitations, accord- 

 ing to their intensity or nature, act on these organs. 

 We have measured the rapidity with which that still 

 mysterious agent, which bears to the muscles the order 

 for motion, travels in the nerves and in tlie spinal 

 marrow. We have separated the action of the nius- 

 ■cles in their elements, — undulatory vibrations which 

 traverse the length of the muscular fibre. Finally, 

 we have studied the nature of contractions, and know 

 how fatigue, heat, cold, and poisons affect these 

 movements. 



On the other hand, while considering the mechani- 

 ■cal conditions of animal locomotion, we have deter- 

 mined, from a kinematic stand-point, the characters of 

 ■the various movements of man and animals. We have 

 classified according to their kind the different bony 

 Jevers of the skeleton, have determined the centres 

 and radii of curvature of the joints, and have esti- 

 mated the momentum of the opposing forces which 

 represent the power and the resistance in the animal 

 machinery. 



It appears now that every thing is ready, and that 

 physiologists have only to apply these studies to the 

 various problems of practical life. They will teach 

 us, doubtless, how best to utilize the muscular work of 

 man and of the domestic animals; they will lay down 

 rules which shall control the physical exercises of 

 the young, the work of the artisan, the drill of the 

 soldier. 



Unfortunately it is not so. Limited as they are, 

 physiologists are scarcely able to study the vital func- 

 tions in man and the more important animals ; 

 besides, the usual method, vivisection, which has dis- 

 closed so much in regard to the properties of tlie tis- 

 sues and the functions of separate organs, cannot 

 discover the regular action of normal life. 



The writer of this article has spent long years in 

 his search for methods and an apparatus capable of 

 faithfully interpreting the external signs of the func- 

 tions of life. The pulsations of the heart or the arte- 

 ries, the respiratory movements, the contractions of 

 the muscles, record themselves with this apparatus, 

 and obtain, for analysis, curves in which the least de- 

 tails of the movements are represented. The object 

 of other instruments is to trace the course traversed 

 by a man or by an animal, or to express the efforts 

 developed as functions of the time. Recently, instan- 

 taneous photography has completed the knowledge 

 of physiological movements, so that to-day we can 

 easily solve most of the problems of the animal mech- 

 anism. 



But if the methods were perfected, if new appara- 

 tus were invented, all the difficulties would not be re- 

 moved; for it is not in the ordinary physiological 

 laboratories that one can study the motions of a bird 

 on the wing, of a galloping horse, or of a man walk- 

 ing, running, or performing some other muscular ex- 

 ercise. It w-as to promote these researches on the 

 physiology of man and animals, that the physiologi- 

 cal station, of which we will give a description, was 

 erected. 



Only the municipal council of Paris could grant 

 land adequate for this kind of experiments. There 

 was a very convenient place on the Avenue de.s 

 Princes, near the Porte d'Auteuil. With the gener- 

 osity always shown when science is concerned, the 

 council granted these lands, and even voted a subsidy 

 to cover a part of the expense of experiments. On 

 the other side, Mr. Jules Ferry, the minister of pub- 

 lic instruction, pleaded warmly before the chambers 

 in favor of llie contemplated establishment. A law, 

 passed in August, ISSL', granted the sums for the con- 

 struction of the necessary buildings. The work was 

 pushed actively forward during the last autumn and 

 winter, and in March experiments were begun at the 

 physiological station. 



The practical applications of physiology are infinite; 

 but in this vast number there are certain (|Uestions 

 whose solution is near at hand, certain others for 

 which nothing is prepared. The management of the 

 physiological station, although the subsequent needs 

 are foreseen, is, for the present, arranged for the 

 study of the animal mechanism; and the experiments 

 under progress relate to human locomotion. 



The problems which i>resent themselves first of all 

 are the following: 1°. To determine the series of 

 motions which are produced in human locomotion of 

 various kinds, — walking, running, leaping; 2°. To 

 search for the external conditions which influence 

 these motions; those, for instance, which increase the 

 rapidity of pace or the length of step, and which thus 

 exercise a favorable or an unfavorable influence up- 

 on the locomotion of man ; 3°. To measure the en- 

 ergy expended each instant, in the various acts of 

 locomotion, in order to discover the most favorable 

 conditions for the utilization of this energy. Instan- 

 taneous photography, and various other appliances of 

 the graphic method, help to solve these problems, 

 which are impossible to direct observation. 



Before entering into the details of the experiments, 

 we will describe the general arrangement of the physi- 

 ological station. Fig 1. shows the land and the build- 

 ing as a whole. A circular and perfectly level course 

 is laid out in a piece of ground used by the city of 

 Paris as a nursery. This course has two concentric 

 track's: the inner one, four metres wide, is for horses; 

 the outer one, for men. Around these tracks runs a 

 telegraph-line, whose poles are fifty metres apart. 

 Every time a walker passes a post, he causes a tele- 

 graphic signal ; an<l this is recorded in one of the 

 rooms of the principal building. We shall refer later 

 to this kind of automatic record, by means of which, 

 for every minute, the rapidity of the walk, the accel- 

 erations and diminutions, and even the number of 

 steps, may be known. In the centre of the course is 

 an elevated platform, on which a merhanical drum 

 beats the time for the step. This drum is worked by 

 a special telegraph-line, coming from a room in the 

 large building where the rhythm is maintained by a 

 mechanical interrupter. 



From the centre of the course runs an iron track, 

 on which rolls a little carriage forming a photographic 

 studio. From within this apartment a set of instan- 

 taneous pictures of the men and horses whose gaits 



