SCIENCE. 



191 



expansi/e force of the gas equals the resistance by the 

 weight or friction of the movable wall, the latter will 

 move and our thermometer, indicating the temperature in 

 the interior of the vessel, will record a fall of temper- 

 ature. Heat has " become latent," has disappeared, be- 

 cause it has done work, has moved the wall. 



It is, therefore, not in accordance with the facts, if Mr. 

 Morris states that a thing may be in a heated state and 

 yet not contain heat. Nor is it true that " as density 

 diminishes the heat capacity increases." The true state 

 of things is evident from the examples given. Since 

 diminution of density is effected by heat, is the work of 

 heat, the gas thus expanded does not contain more, but 

 less heat. The attenuation, the change of its state of 

 cohesion, is the action of a certain amount of heat, and 

 this heat has " become latent," has disappeared as heat, 

 but it nevertheless exists in the expanded gas as a greater 

 range of mobility, as diminished density. On condensa- 

 tion this heat again reappears, i. e. the range of mobility 

 of the gas is diminished, and the motion, potentiality, en- 

 ergy or whatever name Mr. Morris should prefer to apply 

 to this causa efficiens, is transformed into heat. This is, 

 by the way, the very process that is supposed to have 

 been going on in the Laplace "Chaos," and, therefore, 

 proves again the discrepancy between the principle of 

 the conservation of energy and the assumption that the 

 primordial nebula was a " fire-mist," as Mr. Larkin has 

 correctly explained. 



As to Mr. Moiris' conception of the action" of gravita- 

 tion, it seems still more erroneous. This gentleman says: 

 " The earth must fall towards the body with the same 

 energy that the body displays in falling towards the 

 earth." Now, the two fundamental laws of gravitation, 

 as first discovered by Newton are : Attraction acts in 

 direct proportion to mass and in indirect proportion to 

 the square of the distance. 



The statement of Mr. Morris, therefore, is absolutely 

 false. 



Nor is this all. The possibility that gravity can act 

 lies in the space given for the fall of a body acted upon. 

 If, therefore, a body should fall, it must be raised first to 

 allow it space in which to fall. If by some force 100 

 pounds are raised to the height of one foot, this body, if 

 unsupported, will by its fall develop the very same force 

 as was employed to raise it previously, viz.: 100 foot- 

 pounds. In striking on some resistance, say the surface 

 of the earth, it will develop an amount of heat, equiva- 

 lent to its mechanical force 100 foot-pounds = 100 ca- 

 lorics or (small) heat units. Mr. Morris ignores the ele- 

 ment of space, in so far as it must always have been 

 previously furnished. He says : 



" The motion that exists in a falling body was not cre- 

 ated for the purpose. It existed in the falling body in 

 some other form and has simply been transformed, not 

 created." 



But nobody ever contended that it was created. The 

 possibility of its fall was given to the body by some ele- 

 vating force, and it is the very same force which, having 

 existed as potentiality to fall, as long as the body was 

 supported, is transformed into motion, into falling, as 

 soon as the support is withdrawn. And this fall is 

 therefore not due to " internal forces " but to gravity 

 and the space furnished by previous raising. 



But is the discrepancy laid bare by Mr. Larkin the 

 only one existing in regard to the Nebular Hypothesis ? 

 Nay, is this hypothesis really the true history of the 

 world, and of our planetary system in particular ? Is it as 

 free from uncertainties and as little at variance with ob- 

 served facts, as an hypothesis, which has found such 

 ready credence and such universal approval, should be ? 



I believe it has no claim to such confidence as has 

 been bestowed upon it, and since I have gone so far, I 

 might just as well state a few reasons for my conviction, 

 which I am glad to say is shared, or rather also held, 

 by one of our first astronomers. This 1 shall do further 



on, but at present would beg to call the attention of 

 your readers to two other discrepancies which exist be- 

 tween the principle of the conservation of energy and the 

 Nebular Hypothesis — assuming, for argument's sake, the 

 truth of the latter. 



They may be best stated by two questions, to wit : 



1. What existed before "Chaos," and how was 

 " Chaos " brought about ? 



2. How long and by what influence did " Chaos " re- 

 main at rest, and what cause acted on it to force it into 

 formative action ? 



I have never been able to get a satisfactory answer to 

 these questions, nor have I been successful in answering 

 them myself. They seem to convey the impression that 

 a most glaring discrepancy with " conservation of 

 energy " exists in this matter, of which every reader may 

 become convinced on mature reflection. 



For, in the light of the principle of the conservation of 

 energy, motionless matter is an impossibility, as it is to- 

 tally inconceivable to our understanding in every aspect. 

 Again : Why should attraction — if we suppose that it was 

 dormant while the primordial nebula was forming — sud- 

 denly begin to act? What force, what cause, instigated 

 this action at a particular moment ? 



It has been said, and truly, I think, that it is a very 

 cheap and easy matter to write upon the Nebular Hypoth- 

 esis. But is it also an easy thing to write against this 

 hypothesis? From the fact that it is rarely done, it 

 would appear that it is not ; and yet there are dozens of 

 facts and arguments to be brought against it. of these 

 I will only name the more prominent ones, without going 

 into detail : 



The eccentricity of all planetary and lunar orbits. 



The various deviations of the planes of all the planetary 

 and lunar orbits from each other. 



The retrograde motion of the moons of Uranus and of 

 that of Neptune. 



The composition of the rings of Saturn. 



The greater velocity of revolution of the innermost 

 portions of the rings than that of Saturn's surface. 



The greater velocity of revolution of the inner moon 

 of Mars than that of the latter's surface. 



The immense number of comets and meteorites ; their 

 great eccentricities ; the considerable number that have 

 retrograde motion ; the absence of any planetary nebula, 

 so-called, which would allow of being interpreted as an 

 initiatory stage of the formation of a solar system. 



The multiple stars, etc. 



The elaboration of the vaiious facts above stated and 

 several others* would far exceed the proper limits of this 

 communication — which have, indeed, been rather over- 

 stepped already. I may be allowed, however, to add 

 what Prof. Asaph Hall, to whom the paper described in 

 the foot-note was submitted, wrote in reply : 



"To me the Nebular Hypothesis is a very doubtful thing. 

 The facts you mention are against it. Possibly its sup- 

 porters may fudge it so that it will last a little longer, but 

 it is always unsafe to rest on a theory based largely on 

 our ignorance." 



As may be imagined, I was very agreeably surprised by 

 this card and asked Prof. Hall's permission to make use 

 of it in case occasion should offer. This permission the 

 excellent gentleman first declined to give ; his reasons for 

 so doing were stated in the following language : 



" Such questions as the Nebular Hypothesis will only 

 be decided by the slow growth of observation and knowl- 

 edge and not by the opinion of this man or that. I have 

 but little faith in it " 



After some further expostulation on my part, this per- 

 mission was kindly given in a letter, written December 9, 

 1879. Not, however, until now have I made any use of 



* This I have done in a paper published in tiie November and December 

 issues of the Gaea of the 1878, edited by Dr. Hermann KJein, at Cologne, 

 Germany, 



