464 Life of Coimt Rumford. 



down as was that of air, though the mixture does not 

 affect the specific qualities of either of the fluids, and 

 merely embarrasses their internal motions." He then 

 proceeded to connect these experiments with those 

 which he had made on the various substances used in 

 forming artificial clothing for confining heat. The 

 Count follows the results he had obtained as guides in 

 tracing out the tokens " of the wisdom of the Creator 



9 



of the world " in the provisions made in the animal 

 and vegetable kingdoms for preserving the life of 

 plants and living creatures, according to the proportion 

 of fluids and solids in them, and the risk of congela- 

 tion. An illustration of these provisions he finds in the 

 fact that the sap of all trees which are capable of sup- 

 porting a long continuance of frost grows thick and 

 viscous on the approach of the winter. To this in- 

 creased viscosity of the sap in winter are to be added 

 the extreme smallness of the vessels through which the 

 sap moves in vegetables and in large trees, the fact that 

 the substance of these small tubes is one of the best non- 

 conductors of heat, and also the protection furnished 

 by a thick covering of bark. He thus accounts for the 

 preservation of the life of trees through a long and hard 

 winter. The Count had observed the extreme dif- 

 ficulty with which heat passes into wood, when he 

 noticed in his foundry, at Munich, that the fireman 

 stirred the melted metal with a wooden instrument, 

 which was found not to be affected through even one 

 twentieth of an inch within its surface by the glowing 

 fire. The less watery fruits are, the longer will they 

 bear the cold without freezing. 



The Count next devised a more elaborate mechanical 

 contrivance for investigating the internal motions among 



