58 



NATURE 



[November 15, 1894 



in a stretched liquid. His explanation is ingenious : that the 

 close contact of the bodies liberates from a denser surface layer, 

 liquid which will go to supply the prevailing demand, and so 

 lower the energy of the stretched liquid 



Whether this be a quite correct explanation or not, does not 

 the experiment suggest the possibility of an analogous phen- 

 omenon occurring in a tensile ether in which matter is immersed ; 

 giving rise to the effects which we appreciate as gravitational 

 attraction? J. JoLY. 



Trinity College, Dublin, November 6. 



Homogeneity of Structure the Source of Crystal 

 Symmetry. 



To the lucid notice of my paper, '■ Ueber die geometrischen 

 Eigenschaften homogener starrer Slrukturen und ihre 

 Anwendung auf Krystalle," contained in your issue of October 

 1 8, it is perhaps desirable to add a remark. 



The paper referred to is purely geometrical ; it starts with a 

 de&nition, and not with a supposition. Consequently the various 

 new theories advanced by the writers referred to in the notice 

 receive no support Irom il. 



Homogeneity of structure pure and simple, unaided by any 

 theory as to the nature of matter, leads inevitably to all the 

 varieties of symmetry presented by crystals. It is useless, 

 therefore, to look to the facts as to this symmetry for any light 

 upon the vexed question whether the seat of the symmetry is in 

 the arrangement or in the configuration of the molecules, or, 

 indeed, for any proof of the existence of molecules or separable 

 units. \Vm. 1!.\rlow. 



Muswell Hill. 



THE PRESENT STATE OF PHYSIOLOGICAL 

 RESEARCH. 



THE following extracts from an article by Prof. Max 

 Verworn, of Jena, on " Modern Physiology," pub- 

 lished in the Moni'st for April 1894, seem to be well 

 worth the attention of English biologists. It would be 

 interesting to obtain in the pages of X.\tlre an ex- 

 pression of opinion from our physiologists as to how far 

 the reproach is true, that "in treading the beaten paths 

 we are making no progress in physiology, and have stood 

 still for years on the same spot." How far is it true that 

 physiologists must revert to the point of view of com- 

 parative physiology, or the physiology of the endless 

 variety of lower and simpler forms of life which was that 

 which formerly so fruitfully shaped the research of the 

 great master Johannes Muller? Is it, or is it not, time that 

 the methods of horological physiology were less dominant 

 and gave place to a determined and persistent study of 

 living structure in many of its varied manifestations 

 other than the frog and the rabbit ? 



" Psychologically, it is a highly interesting phenomenon, and 

 one of moment in the history of science, that now, almost 

 immediately after the final suppression of the old vitalism by 

 the new development of the natural sciences, we have again 

 arrived at a point which corresponds in the minutest details to 

 the reversion lo mystical viialism which took place after the 

 clear and successful research of the preceding century. As a 

 fact, the parallel between the conditions of the eighteenth 

 century and those of to-day is unmistakable. Now, as then, 

 the physico-chemical method of explaining phenomena of life 

 looks back on a brilliant, almost dazzling sequence of successes ; 

 now, as then, the tracing of vital processes to physical and 

 chemical laws has re.'<chcd a point at which, for many years, 

 with the methods now at our command, no essential progress 

 has been made, where, on the paths hitherto trodden, a 

 boundary line is everywhere distinctly marked ; and now, as 

 then, on the horizon of science the ghusi of a vital force looms 

 up. It has already t.ikcn posses-ion of the minds of serious 

 thinkers in Germ.iny, with the dire prospect of more extensive 

 conquests ; and in I- ranee, too, it would seem, science is slowly 

 opening its door to this invasion of genuine mysticism. 



"To underpitand this phenomenon psychologically, and to 

 acquaint ourselves with the means lA slaving off a general 

 reaction into vitalism, it ii desirable to examine more carefully 



NO 1307. VOL. 51] 



the present state of physiology. A review of the productions 

 which appear in our different physiological journals, which will 

 best exhibit the present state and tendency of the science, 

 furnishes an extremely remarkable spectacle. Leaving aside 

 the science of physiological chemistr)', which is independently 

 developing with great success, we find, with the exception of a 

 few good contributions to the physiology of the central nervous 

 system, as a rule, only extremely special performances of very 

 limited scope and import, wholly without significance for the 

 greater problems of physiology, whether practical or theoretical, 

 and exhibiting no connection whatever with any well-delined 

 general problem of physiology. In fact, what is called physio- 

 logy is beginning here and there to degenerate into mere tech- 

 nical child's play. With every new number of our physiological 

 magazines, the unprejudiced observer is gradually gaining the 

 conviction that general problems of physiology no longer exist, 

 but that inquirers, driven to desperation in the struggle for 

 material, have no choice but to hunt up the old dry bones of 

 science, on which they fall with the nervous rapacity of hungry 

 dogs. And in the case of most of the productions, this im- 

 pression is strengthened by the fact that the results, when once 

 found, are wholly disproportionate to the tremendous expendi- 

 ture of labour and time which it might be seen beforehand they 

 would require. .\nd yet all the lime the great problems of 

 physiology everywhere stare us in the face and seek solution. 

 For. if we regard the problem of physiology as the investig.ition 

 of the phenomena of life, we are certainly yet very far from the 

 solution of even its most important and most general problems. 

 We need not go to the extreme that Bunge does in his excellent 

 text-book of physiological chemistry, of maintaining that the 

 phenomena of our organism which we have explained mechani- 

 cally are not genuine vital processes at all, no more than is 

 ' the motion of the leaves and branches of a tree shaken by a 

 storm, or the motion of the pollen which the wind wafts from 

 the male to ihe female poplar.' Hut it is certainly no ex- 

 aggeration to say that what the splendidly-conceived methods 

 of the gre.it masters of physiology since Johannes Midler havc 

 explained, are not elementary processes of life, but almns: 

 exclusively the crude physical and chemical actions of llic 

 human body. 



"For what have we attained? We have measured and 

 registered the motions of respiration, the mechanics of the 

 gaseous exchange in the lungs in their minutest details. We 

 know the motions of the heart, the circulation of the blood in 

 the vascular system, nay, even the slightest variations of Ihe 

 pressure of the blood, as produced by the most diverse causes, 

 as accurately as we do the phenomena of hydrodynamics in 

 physics. We know ihat respiration and the motion of the heart 

 are conditioned by the automatic activity of nervous centres in 

 the brain, but no spirometer, no kymogrnph, no measuring or 

 registering apparatus can give us the slightest idea of whal 

 takes place in Ihe nerve-cells of the brain that condition the 

 healing of the heart and respiration. 



'■ Further, we have investigated the motions of the muscles, 

 their dependence on the most diverse factors, their mechanical 

 powers, their production of heat and electricity, as exhaustively 

 as only the phenomena of the special departments of mechanical 

 physics have hitherto been treated. Uut of wliat goes forward 

 in the minute muscle-cells during simple muscular contraction, 

 no myograph, no galvanometer has as yet given us the slightest 

 hint. 



" We know also the laws of the excitability of Ihe nervous 

 fibres, of the propagation of irritations, of the direction and 

 velocity of nervous transmission, thanks to ihe ingenious 

 methods of recent physiology, in all their details. Hut of what 

 is enacted during these processes in the nerve-libres and in the 

 ganglion-cell from which it ramifies, no induction-apparatus or 

 muliiplicalor can give us the least information. 



" We know beMdes, that the heal and electricity produced by 

 the body, and ihc mechanical energy of mu-cular work, are the 

 consequence of Ihe transformation of the chemical energy which 

 we have taken into our bodies with our food. Hut by means 

 of what chemical processes the cells of the individual structures 

 take part in these achievements, the most sensitive thermo- 

 meter or calorimeter will not disclose, and no thermal pile or 

 graphical apparatus will indicate. 



" We might give any number of examples of this kind, but 

 those adduced exhibit distinctly enough the point lo be sigua- 

 lised. What we have hitherto attained is this; we have 

 measured, weighed, described, and rcgisleied the gross 



