256 



NATURE 



\yan. 12, 1888 



as gravitation, and to avoid it on the earth is impos- 

 sible ; and with this conclusion vanishes all hope of a 

 perpetual motion machine. If we are inclined to regret 

 this fact, a little reflection on what would occur if friction 

 ceased to act may not be uninstructive, for the whole face 

 of Nature v/ould be at once changed, and much of the 

 dry land, and, even more rapidly, most of our buildings, 

 would disappear beneath the sea. Such inhabitants as 

 remained for a short time alive would not only be unable 

 to provide themselves with fire or warmth, but would 

 find their very clothes falling back to the original fibre 

 from which they were made ; and if not destroyed in one 

 of the many possible ways — such as by falling meteors, no 

 longer dissipated by friction through the air, or by falling 

 masses of water, no longer retarded by the atmosphere 

 and descending as rain — would be unable to obtain food, 

 from inability to move themselves by any ordinary method 

 of locomotion, or, what would be equally serious, having 

 once started into motion, from being unable to stop 

 except when they came into collision with other unhappy 

 beings or moving bodies. Before long they, with all 

 heavier substances, would disappear for ever beneath the 

 waters which would now cover the face of a lifeless 

 world. 



We turn to the motion of planetary bodies — is 

 that perpetual ? At first, everything seems to show 

 that it is. The earth with its mass of 3000 trillion 

 tons turns with a speed which enables a student to 

 go bare-headed a good many miles without catching cold 

 in the act of saluting a Professor, for a long time 

 defied all attempts to detect in it loss of speed ; but 

 with the friction of the tides continually af work such 

 loss must take place, and now it is pretty certain from 

 the calculations of Adams, the astronomer, that the earth 

 loses about an hour in 16,000 years, and is coniing to 

 rest, though it must be admitted rather leisurely. So, 

 also, the hurrying up of the comets as they go round 

 the sun is possibly accounted for by a retarding action 

 in space which makes it necessary for them to try 

 and make up, as it were, for lost time ; and in fact the 

 general arguments in the present day are in favour of 

 what Sir Isaac Newton believed — that the motions of all 

 bodies in space are suffering retardation, and that their 

 velocity is becoming less and will ultimately cease. 



Perpetual motion, then, is impossible. By no means. 

 We have duly considered motion of matter in its visible 

 and mechanical form, and if the foregoing remarks are 

 true, then in this form assuredly it is ; but there is, as we 

 have seen, the great fact of indestructibility of energy, 

 and the greatest generalization of the present century is 

 that which accounts for the disappearance of energy in the 

 form of mechanical and visible motion by showing that an 

 exactly equal amount appears in the form of molecular 

 and invisible motion. To this all outward motion tend-, 

 and friction is theagency by which the change is effected. 

 Down to a certain point the change can be effected in 

 either direction, and the heat-engine converts molecular 

 motion into mechanical, again to be reconverted into 

 molecular motion in all its working parts, as well as in 

 connection with the useful work it does. This stage 

 reached, there is no process known to us by which the 

 cycle can be continued, and the term " degradation," in 

 the sense of having gone down a step, but nevertheless 

 a step which can never be reclaimed, is applied to the 

 tendency of energy to assume molecular form by dissi- 

 pation over a larger mass of matter, so that its effect 

 is less intense, though equal numerically in amount. To 

 this all Nature tends, and beyond this point we cannot 

 go. Here, at any rate, the motion is perpetual, but it 

 is motion that tends to approach a state unsatisfactory 

 to the instinct of the humnn mind. Great intellects, 

 such as Rankine and Siemens, have striven to con- 

 jecture ways at present unknown to us by which the 

 energy now spreading itself over the vast expanse of 



space may be gathered again and regenerated, so that we 

 may look forward not to the lowest but to the highest 

 form of motion as that which, passing through all its 

 cycles, shall last for ever. 



THE CHAIR OF DARWINISM IN PARIS. 



/^NE of the most interesting evidences of the differing 

 ^ ^ results of municipal organization in foreign countries, 

 as compared with those resulting from such organization 

 in our own, is the news that the Municipal Council of 

 Paris intends to found (in connection with the Sorbonne, 

 or the Jardin des Plantes, or the College de France, we 

 do not know which) a Chair of Philosophical Zoology, 

 with a special view to the propagation of the doctrine of 

 evolution as elaborated by Darwin. It appears that the 

 official naturalists in France— those holding the leading 

 professorships and museum appointments — have not 

 hitherto been very friendly to Darwinian doctrine. The 

 Municipal Council of Pans has recognized the fact that 

 there is an undesirable hostility to Darwin's views 

 amongst the official group, and actually proposes to 

 remedy the evil results of this hostility by establishing 

 a new Chair, destined to give fair play and a full hearing 

 to the new philosophy. It is as though the Corporation 

 of London should propose to build and endow a labora- 

 tory of physiological experiment or of bacteriology. The 

 imagination recoils before the task of picturing Mr. 

 Alderman Greenfat expounding to his colleagues the 

 importance to the community of scientific research, and 

 carrying with him a large majority in favour of a. scien- 

 tific enterprise hitherto neglected and even penalized by 

 middle-class authority. 



Tnere is very little doubt as to who is the fittest man in 

 France at this moment to hold such a Chair as that which 

 is now to be created. M. Giard, for many years Professor 

 of Zoology at Lille, and only this year called to a similar 

 Chair in Paris, has not only been the first in France to 

 teach from an ofiicial position the doctrine of evolution in 

 zoology, but has made many most valuable researches 

 himself, and has created a school amongst whom are the 

 ablest of the younger French zoologists. Every embryo- 

 logist knows the works not only of Alfred Giard, but 

 those of his pupils Barrois, Halley, Monnet, and others. 

 Alfred Giard had to submit to some painful remon- 

 strances, and to imperil his official career as a Pro- 

 fessor of Zoology in France, when he determined to break 

 with the traditions of his eminent master, Henri de 

 Lacaze Duthiers, and to boldly accept Darwinism and the 

 methods of the modern English and German school. It 

 is therefore only right that his name should be the first to 

 be considered in relation to the new Chair in Paris, and 

 we have no hesitation in saying that, should he be 

 appointed, a man will have been secured as the first 

 occupant of a difficult position whose qualifications render 

 it certain that he will not only do credit to himself, but 

 will justify, by his successful teaching, the enlightened, 

 patriotic, and high-minded initiative of the Municipality 

 of Paris. E. R. L. 



NOTES.. 



On the 3rd of this month there passed away a Scottish parish 

 minister, who though not himself a scientific man has come in 

 contact with three successive generations of men of science 

 whom the love of travel or of geology has led to the i)ictures'.iue 

 island of Skye. The Rev. Dr. Donald Mackinfion was the thid 

 of his family who have been ministers of the parish of Strath. 

 His grandfather was appointed to the incumbency in 1777, and 

 held it for forty-nine years. His father took the office in 1826, 

 and held it for thirty years, until he himself succeeded to it in 

 1856. The parish has thus been presided over by the same 

 family for 'he long period of 1 10 years. Unfortunately none of 



