WHERE DID LIFE BEGIN? jj 



Even after these admissions one embarrassment presents itself, hap- 

 pily, however, not affecting the argument, viz. : 



So fully has every conceivable inference, every supposable fact 

 and phenomenon in the development and history of the earth, been 

 reviewed and discussed over and over again, in the light of this primi- 

 tive glowing molten mass, by able and discriminating writers, that it 

 may seem presumptuous at this late day to attempt any new deduc- 

 tion, or to draw any new conclusion radically important, touching this 

 matter. But if the views here presented have been expressed before, 

 in the relation of cause and effect, the writer has not been fortunate 

 enough to meet with them, and it is quite safe to say that if they are 

 correct their significance as a factor in other problems at least will 

 not be questioned. 



, It is not claimed that these views have been proved to be true 

 inductively, but there are certain facts and phenomena pointing di- 

 rectly to definite conclusions hereinafter stated which I am sure every 

 one holding and believing that the earth was at one time a molten 

 mass will find it easier and more reasonable to admit than to deny. 



Regarding the earth, then, as at one time an intensely hot globe, 

 totally destitute of organic life, one of the principal and indispensable 

 conditions of rendering it habitable for plants and animals evidently 

 would be the radiation into space of its excessive and destructive heat. 

 The accomplishment of this, with the train of concurrent effects which 

 would follow, or at least ever have followed the gradual reduction of 

 temperature, is all that would be necessary to render the earth a suit- 

 able place for the maintenance of vegetal and animal life. At any 

 rate this is precisely what has taken place since the commencement of 

 the Azoic age, and is still taking place on parts of the earth's surface 

 to-day, visible and obvious to any observer. 



Our inquiiy, therefore, is reduced to this question : What part or 

 parts of the earth's surface first became sufiiciently cooled by radiation 

 to be habitable by plants and animals ? 



A supposed case may help us in reaching a correct answer to this 

 question. Let us assume, then, that the earth, at the time it was a 

 molten mass, had been and was revolving in an orbit so near the sun 

 that the amount of heat it would have been receiving from the sun 

 would have just equalized the amount of heat it was losing by radia- 

 tion. Under these conditions it would have cooled as the sun cooled 

 — neither faster nor slower. This helps us to understand that the heat 

 received by the earth from the sun is, and ever has been, an offset, so 

 far as it goes, to the heat lost from the earth by radiation. A state- 

 ment of the loss of heat from the earth during any definite time may 

 be formulated in this way : From the heat lost by the earth by radia- 

 tion during a given period subtract the heat received by the earth from 

 the sun during the same period, and the remainder will be the earth's 

 net or actual loss of heat. Sidereal heat received by the earth being 



