262 THE SCHOOL OF REAUMUR 



in an unfertilised egg, however, putrefaction would go 

 on faster when the egg was moderately warmed. 



Reaumur, we see, had attained a clear knowledge of 

 some of the elementary conditions of the problem ; it 

 was not possible for him to explain why putrefaction 

 should set in only between certain extremes of tem- 

 perature, and should become more energetic as blood- 

 heat is approached. The part which bacteria play in 

 putrefaction was not suspected as yet. 



Pupse confined in a glass flask sometimes exude a 

 considerable amount of moisture, which condenses on 

 the sides of the flask. The exudation seemed to Eeaumur 

 a necessary accompaniment of the consolidation of watery 

 liquids into permanent tissues. Exudation is a sign of 

 life and growth ; more remotely a sign of approaching 

 death and decay. All growth, all activity, is a step 

 towards the wearing-out of the body. It occurred to 

 him that life might be indefinitely prolonged if the 

 exudation was checked. Accordingly he varnished the 

 body of a pupa, carefully leaving the spiracles unob- 

 structed, and found that the emergence of the moth was 

 retarded by some weeks. He went on to infer that in 

 man himself a similar prolongation of life was conceivable. 

 Cold, or a retardation of the insensible perspiration, 

 might possibly be employed to protract life indefinitely, 

 if such a result were truly desirable.^ 



Reaumur carried his speculations to a length that was 

 not quite prudent, and thereby laid himself open to a 

 mischievous critic. Maupertuis, a friend and ally of 

 Reaumur's, seized upon the notion of protracting life by 

 checking the insensible perspiration, and published his 

 thoughts in a volume of letters, together with many 



^ Bacon {Hist, of Life and Deathy ch. xviii) had explained that there is in 

 the bodies of animals a vapour analogous to flame ; if this is prevented from 

 escaping, by unction with oil, life will be prolonged. 



