June 27, 1889] 



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199 



veiling to Paris for inoculation and unable to sup- 

 port themselves ; and thirdly, a strong resolution 

 ■calling upon the Privy Council to instantly inaugurate 

 such muzzling and other restrictive measures as shall 

 definitely and finally exterminate rabies. The anti-vivi- 

 section agitators, whose object it is apparently to keep 

 alive rabies in this country, have opposed the meet- 

 ing, which we hope will be crowded by genuine lovers 

 of men and animals. The form their opposition has 

 taken is amusing to the last degree, since it consists 

 of a petition, advertised in the daily papers, made 

 of four or five headings, each of which may be called 

 in question. In the very first paragraph it is stated 

 that the Manager of the Dogs' Home in Battersea 

 has passed a large number of dogs through his hands, 

 and that he never saw a case of rabies among 

 them. If this means that there has never been a 

 case of rabies at the dogs' home, we believe evidence 

 can be produced to the contrary. 



The innate falsity of this agitation is always 

 making itself felt, and it is nothing more than 

 Nemesis that the statements made by agitators in the 

 hope of deceiving the public, should be detected and 

 exposed again and again. Such a stateaient as that 

 asserted to have been made by the Manager, even 

 if he did make it, has no value in view of the in- 

 controvertible facts of the police records of the ex- 

 istence — nay, more, of the increase — of rabies in 

 London. The Mansion House meeting will do much to 

 blow away this miserable opposition, which attacks bio- 

 logical science alone, knowing full well that no false sen- 

 timent can be hashed up against physical science and its 

 benefits to mankind. The object of the meeting is to 

 honestly acknowledge our great indebtedness to M. 

 Pasteur, to provide for our poorer fellow-countrymen gain- 

 ing the benefits of the Pasteur Institute, and, finally, to 

 stamp out rabies. 



No scientific man who really has the interests — in fact, 

 the honour — of his country at heart will refuse his sup- 

 port on this important occasion ; and we may well hope 

 that many will be found able to attend the meeting 

 personally, to render the occasion worthy of the great 

 chemist whose work has so essentially led to the suc- 

 cessful performance of the hygienic measures now about 

 to be executed. 



STELLAR EVOLUTION. 



Stellar Evolution and its Relation to Geological Time. 

 By James Croll, LL.D,, F.R.S. (London: Edward 

 Stanford, 1889.) 



DR. CROLL'S book, though chiefly dealing with the 

 question of stellar evolution from the astronomer's 

 point of view, calls in the evidence afforded by geology 

 in favour of the theory which is set forth in its pages. 

 The particulars of the theory are clearly stated, and the 

 new facts which have been gathered since the theory was 

 first published are fully considered. 



Dr. CroU accepts the nebular hypothesis of Kant and 

 Laplace, atid deals mainly with the question of the pre- 



nebular condition. According to his theory, large cool 

 dark bodies, moving with enormous velocities, were either 

 created or were eternal ; and these colliding with each 

 other here and there, the evolution of the celestial bodies 

 was accomplished. With regard to the origin of these 

 bodies endowed with motion, Dr. Croll states : — " We 

 are perfectly at liberty to begin by assuming the exist- 

 ence of stellar masses in motion ; for we are not called 

 upon to explain how the masses obtained their motion, 

 any more than we have to explain how they came into 

 existence. If the masses were created, they may as 

 likely have been created in motion as at rest ; and if 

 they were eternal, they may as likely have been eternally 

 in motion as eternally at rest" (p. 3). It is argued that 

 the heat energy which would have been derived from 

 gravitation alone could not possibly have been equal to 

 that which the solar system originally possessed. But 

 there is absolutely no limit to the amount of available 

 energy from Dr. CroU's point of view. The most im- 

 portant argument against the gravitational theory is 

 undoubtedly the geological and biological one. The 

 whole question of geological time rests on an estimation 

 of the time during which the sun has been radiating its 

 heat, and on this point Dr. Croll remarks : " If gravita- 

 tion be the only source from which the sun has derived 

 its heat, then life on the globe cannot possibly date 

 farther back than 20,003,000 years, for under no possible 

 form could gravitation have afforded, at the present rate 

 of radiation, sufficient heat for a longer period " (p. 35). 

 The adoption of Langley's value (17 times thatof Pouillet) 

 for the rate of solar radiation reduces Helmholtz's 

 estimate of 20,000,000 years to 12,000,000 years, and 

 even this would not ba available for plant and animal 

 life, as millions of years must have undoubtedly elapsed 

 before the earth was prepared for them. Prof. Tait 

 ("Recent Advances in Physical Science," p. 175) 

 has shown that, from the physical point of view, 

 " 10,000,000 years is about the utmost that can be 

 allowed for all the changes that have taken place 

 on the earth's surface since vegetable life of the lowest 

 known form was capable of existing there." Sir William 

 Thomson states his conclusions on this point thus : " In 

 the circumstances, and taking fully into account all 

 possibilities of greater density in the sun's interior, 

 and of greater or less activity of radiation in past 

 ages, it would, I think, be exceedingly rash to assume 

 as probable anything more than 20,000,000 years of the 

 sun's light in the past history of the earth, or to reckon on 

 more than five or six million years of sunlight for time to 

 come " (" Popular Lectures and Addresses," p. 390). 



It is not necessary here to enter into details of the 

 various methods by which geologists and biologists have 

 attempted to estimate the length of time which must 

 have elapsed since the earth first received the heat of the 

 sun. On this point Dr. Croll says: "The grounds upon 

 which the geologists and biologists found the conclusion 

 that it is now more than twenty or thirty millions of years 

 since life began on the earth are far more certain and 

 reliable than the grounds upon which the physicist con- 

 cludes that the period must be less" (p. 68). Here 

 again, it may be well to quote Sir William Thomson, 

 who says: — "What then are vve to think of such 



