June 3, 1887.] 



SCIEW'CE. 



54J 



culate around the centre, blowing obliquely along 

 an inward, ascending, left-handed spiral with in- 

 creasing velocity, until they turn to an outward 

 spiral aloft. The central low pressure in this case 

 is primarily due to its high mean temperature, and 

 secondarily to the centrifugal force of the whirl 

 and the deflective force of the earth's rotation. 

 This is a cyclone with a warm centre. The gen- 

 eral winds of the northern hemisphere constitute 

 a cyclone with a cold centre : their centre of low 

 pressure is at the pole, and their ring of high 

 pressure is around the tropic of Cancer, and, 

 except for the lower member of surface winds, 

 the currents approach the centre aloft, along a 

 left-handed, inward, descending spiral, and turn to 

 an outward spiral below. In this case, the press- 

 ure at the centre would be high, owing to the 

 cold, were it not lowered by the centrifugal force 

 of the whirl. In warm-centred cyclones, the 

 steepest gradients and highest velocities are near 

 the surface ; in cyclones of cold centres, they are 

 in the lofty regions. The enormous progress 

 marked by such a generalization may be appre- 

 ciated by reading the vague and vain theories of 

 other authors. Ferrel's theory of tornadoes is 

 another monument of deductive study, checked 

 by a fulness of knowledge of fact, as far as ob- 

 servations and records allow. 



It is not desu-ed to imply by this reference to 

 deductive methods that meteorological observa- 

 tions and their statistical study should in any way 

 decrease ; they are, of course, the essential foun- 

 dation for further study. But it is a matter of 

 regret that so few willing and interested observers 

 go beyond this foundation -work far enough to 

 discover the intense interest of the broader, phys- 

 ical study of meteorological phenomena. We 

 may take pride in recognizing Espy and Ferrel as 

 leaders in modern meteorology, but we must take 

 care also that they have followers. 



W. M. Davis. 



HYPNOTISM IN FRANCE.' 



The voluntary production of those abnormal 

 conditions of the nerves which to-day are denoted 

 by the term ' hypnotic researches ' has manifested 

 itself in all ages and among most of the nations 

 that are known to us. Within modern times 

 these phenomena were first reduced to a system 

 by Mesmer, and, on this account, for the future 

 deserve the attention of the scientific world. The 

 historical description of this department, if one 

 intends to give a connected account of its develop- 

 ment, and not a series of isolated facts, must be- 

 gin with a notice of Mesmer's personality, and 

 1 Translated for Science from Der Spinx. 



we must not confound the more recent develop- 

 ment of our subject with its past history. 



The period of mesmerism is sufficiently under- 

 stood from the numerous writings on the subject, 

 but it would be a mistake to suppose that in Braid's 

 ' Exposition of hypnotism ' the end of this subject 

 had been reached. In a later work I hope to 

 show that the fundamental ideas of biomagnetism 

 have not only had in all periods of this century 

 capable and enthusiastic advocates, but that even 

 in our day they have been subjected to tests by 

 French and English investigators from which they 

 have issued triumphant. 



The second division of this historical develop- 

 ment is carried on by Braid, whose most impor- 

 tant service was emphasizing the subjectivity of 

 the phenomena. Without any connection with 

 him, and yet by following out almost exactly the 

 same experiments, Professor Heidenhain reached 

 his physiological explanations. A third division 

 is based upon the discovery of the hypnotic con- 

 dition in animals, and connects itself to the ex- 

 perimentum mirabile. In 1872 the first writings 

 on this subject appear from the pen of the i^hysi- 

 ologist Czermak ; and since then the investiga- 

 tions have been continued, pai'ticularly by Profes- 

 sor Preyer. 



While England and Germany were led quite in- 

 dependently to the study of the same phenomena, 

 France experienced a strange development, which 

 shows, as nothing else could, how truth every- 

 where comes to the surface, and from small be- 

 ginnings swells to a flood which carries irresistibly 

 all opposition with it. This fourth division of the 

 history of hypnotism is the more important, be- 

 cause it forms the foundation of a transcendental 

 psychology, and will exert a great influence upon 

 our future culture ; and it is this division to which 

 we wish to turn our attention. We have inten- 

 tionally limited ourselves to a chronological ar- 

 rangement, since a systematic account would 

 necessarily fall into the study of single phe- 

 nomena, and would far exceed the space offered 

 to us. 



James Braid's writings, although they were dis- 

 cussed in detail in Littre and Robin's ' Lexicon, ' 

 were not at all the cause of Dr. Philips' first 

 books, who therefore came more independently 

 to the study of the same phenomena. Braid's 

 theories became known to him later by the ob- 

 servations made upon them in B^raud's 'Ele- 

 ments of physiology,' and in Littre's notes in the 

 translation of Mtiller's ' Handbook of physiology ; ' 

 and he then wrote a second brochure, in which he 

 gave in his allegiance to Braidism. His principal 

 effort was directed to withdrawing the veil of 

 mystery from the occurrences, and by a natural 



