1 86 SECRETS OF EARTH AND SEA 



Oliver), but serves as the vehicle, the receptacle, for this 

 supposed intangible entity " life." In the same imaginative 

 vein, our grandfathers used to say that heat was due to 

 the entity or " fairy " " caloric " which could be enticed 

 into or driven from material bodies, making them " hot " 

 by its presence and cold by its greater or less exclusion. 

 The suspended animation of frozen germs and their return 

 to life when warmed could thus be represented as an 

 affection or affinity between the fairy " Vitalis " and the 

 fairy " Caloric," the former fleeing from the body and 

 waiting near when the latter deserts his place, but returning 

 to happy union with " Caloric " when he again, however 

 feebly, pervades once more the vehicle provided for 

 "Vitalis." Such imaginary essences are not of any 

 assistance to us in arriving at a knowledge of the facts, 

 and so far from helping us to a comprehension of the 

 ultimate nature of things (which we have no reason to 

 suppose that it is possible for us to attain) their intro- 

 duction tends to the substitution of imaginary causes 

 and unverified assumptions for the carefully-tested and 

 demonstrated conclusions of science. 



In 1871 Lord Kelvin, when president of the British 

 Association, suggested that the origin of life as we know 

 it may have been extra-terrestrial, and due to the " moss- 

 grown fragments from the ruins of another world," which 

 reached the earth as meteorites. It was objected to this 

 that the extreme cold very near to the absolute zero 

 which prevails in interstellar space would be fatal to all 

 germs of life carried by such meteoric stones. But twenty 

 years later Sir James Dewar showed that this objection 

 did not hold, since at any rate some forms of life certain 

 bacteria could survive an exposure of several days to a 

 temperature approaching the absolute zero. Later Sir 

 James made some very striking experiments by exposing 

 cultivations of phosphorescent bacteria to the temperature 



