548 AN'IsrUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



of melting ice. Arrh6nius estimates the temperature of nebular 

 space at —220° (53° absolute), taking physical observations as a 

 basis. The germ that is traveling across this space under the impulse 

 of the pressure of radiation must, then, endure for months, years, or 

 even centuries, a temperature of 220° C. below zero; what is going 

 to be the result from the viewpoint of its vitality, and more than 

 all, from the point of view of its germinative power ? 



Modern physicists and physiologists answer this question victo- 

 riously. In the laboratory of the Jenner Institute in London, sci- 

 entists have quite recently met with success in keeping in liquid 

 oxygen for 20 hours, at a temperature of 250° C. below zero, spores of 

 bacteria which have completely retained their gei-minative power 

 after this severe test. And Prof. MacFayder has kept living germs 

 for more than six months at 200° C. below zero, not only without their 

 germinative power having been destroyed, but even without its hav- 

 ing been injured in the slightest degree. 



Svante Arrhenius points out that this preservation of germinative 

 power at very low temperatures is the most natural thing possible. 

 This power, indeed, ought to disappear only under the influence of 

 some chemical reaction, and it is known that these reactions take 

 place more and more slowly as the temperature of the medium is 

 lowered. At the temperature of interstellar space, reactions of life 

 ought to be produced by an activity a thousand million times weaker 

 than at a temperature of 10° C, and at a temperature of 220° C. 

 below zero the power of germination would not diminish more during 

 3,000,000 years than it diminishes in a day at the temperature with 

 which we are familiar, 10° C. below zero.^ All fear in regard to the 

 prolonged action of cold is therefore removed — it is, then, without 

 injurious effect on the germinative faculty of spores. 



Time, acting alone, seems equally harmless. Have not bacteria 

 been found, in fact, in a Roman vault, v/hich have certainly remained 

 untouched for 1,800 years and which, nevertheless, were perfectly 

 capable of germination after this long interval ? 



As to the influence of the absolute aridity of interstellar space, an 

 agency that is added to that of cold and that of time, neither does 

 this appear to be dangerous to our germ of life. Schraeder has shown 

 that a green alga, Pleurococcus, can live three months in a medium 

 that has been completely desiccated by sulphuric acid. Prof. ^la- 

 quenne, of the French Institute, has gone still further. He has demon- 

 strated, with experiment and observation at hand, that seeds can 

 stay several years in a Crookes tube — that is, in almost complete 

 vacuum, without losing their germinative power, and Paul Becquerel 



• Arrhenius. The Evolution of Worlds (Seyrig translation), p. 238. 



