714 Miss Agnes M. ClerJce 



blood, meat and milk, sealed in glass tubes, underwent putrefaction 

 in the ordiuary course after prolonged immersion in liquid oxygen. 

 Nor was the germinating power of seeds impaired by subjection to 

 the ordeal. Seven years later, Dr. Allan Macfadyen carried out an 

 extensive series of experiments of this nature at the Koyal Institution, 

 under the personal supervision of Professor Dewar. The action of 

 liquid air on bacteria was first tested. It proved entirely innocuous. 

 After twenty hours at — 190° C, no diminution in their powers of 

 growth, or in any of their functional activities, was perceptible. 

 Phosphorescent organisms supplied a striking illustration of the 

 alternate suspension and renewal of vital processes by freezing and 

 thawing. Cooled down in liquid air they become non-luminous, but 

 the intra- cellular oxidation producing the phosphorescence recom- 

 menced with full vigour when the temperature was raised. The 

 sudden cessation and rapid renewal of the shining faculty of the cells, 

 despite extreme changes of temperature, were eminently instructive. 

 Seven days in liquid air j>roved no more deleterious to bacterial life 

 than twenty hours. The temperature of liquid hydrogen was tried, 

 with the same upshot; the much-enduring series of organisms dealt 

 with suffered no injury. At 21° absolute, then, and probably much 

 nearer to the zero-point, life can continue to exist. It can continue 

 to exist, that is to say, under conditions bringing about an entire 

 cessation of chemical, and an approximate cessation of molecular, 

 activity. These facts, as Dr. Macfadyen remarked, "afford new 

 ground for reflection as to whether life, after all, is dependent for its 

 continuance on chemical reactions." Biologists, he added, " therefore 

 follow with the keenest interest Professor Dewar's heroic attempts 

 to reach the absolute zero " ; while his success so far has already 

 thrown open to them a new realm of experimentation, and placed in 

 their hands an agent of investigation from the effective use of which 

 they may "hope to gain a little further insight into the great mystery 

 of life itself." The speculative interest of these researches supplies, 

 indeed, the keenest incentive to their prosecution. The transmissi- 

 bility from planet to planet, for instance, of living germs or spores 

 has often been debated ; it is now known that the cold of space 

 would be unlikely to stand in the way. There are, however, other 

 difficulties less easily removable ; nor, even if a cosmic community 

 of bacterial species were established, should we find ourselves any 

 nearer to the heart of the creative mystery of life's origin. 



The development of low-temperature chemistry is one of the 

 most striking features of scientific history during the last decade 

 of the nineteenth century. Many questions of profound interest have 

 been answered through its means, and a partial insight has been 

 gained into some of the most recondite secrets of nature. The 

 unique condition attends it, that the ne phis ultra cannot recede as it 

 advances. The absolute zero forms an irremovable landmark, a 

 boundary-line that may not be transgressed, an asymptote, as it were, 

 to the curve of future progress. And every step nearer to it is 



