SUSPENDED ANIMATION 175 



It is the fact that, from the year 1860 onward, 

 numerous observers have experimented on the influence 

 of very low temperatures upon seeds, and have uniformly 

 shown that the power of germination and healthy growth 

 of the seeds is not destroyed by exposure to very low 

 temperatures. The celebrated Swiss botanist, De Candolle, 

 published the first careful observations on this subject 

 in conjunction with Raoul Pictet, who had devised an 

 apparatus for producing exceedingly low temperatures. 

 Pictet in 1893 exposed various bacteria and also seeds 

 to a temperature of nearly 200 degrees below zero centi- 

 grade without injury to them. They " resumed " their 

 life when gradually restored to the normal temperature. 

 Pictet concluded that since all chemical action of the 

 kind which goes on in living things requires a certain 

 degree of temperature for its occurrence, and that this is 

 demonstrably considerably higher than minus 100 degrees 

 centigrade, we must suppose that all chemical action in 

 living things (as in nearly all other bodies) is annihilated 

 at 100 degrees below zero centigrade. Accordingly he 

 maintained that what we call "life," or "living," is a 

 manifestation of chemical forces similar to those shown 

 in other natural bodies, and liable to interruption and 

 resumption by the operation of unfavourable or favourable 

 conditions as are other chemical processes. In 1897, 

 Mr. Horace Brown and Mr. F. Escombe published, in 

 the Proceedings of the Royal Society of London, an 

 account of experiments in which they exposed seeds of 

 twelve plants belonging to widely different natural orders 

 to a temperature varying from 183 degrees to 192 degrees 

 below zero centigrade for a period of no consecutive 

 hours (about four days and a half). As a result the 

 germinative powers of the seeds showed no appreciable 

 difference from that of seed not subjected to cold, and 

 they produced healthy plants. The low temperature was 



