414 TEMPERATURE AND LIFE. 



One has a right therefore to assume that all flowers evolve a certain 

 amount of heat, variable, it is true, for one flower differs from another, 

 but always clearly appreciable. A similar evolution is observed in the 

 active organs of plants when they are excited to movement. It has 

 been established in tbe case of germs by the means of thermo-electric 

 needles. It is much more sensible than in the case of adult plants, in 

 which life is less active and intense. 



We see in the vegetable, as in the animal kingdom, that heat is gen- 

 erated, and that it is due, for the most part, to oxidations within them- 

 selves. It is possible to establish the existence of a complete likeness 

 between these two classes of organisms. The demonstration which 

 substantiates itself every day of the identity and unity of the funda- 

 mental laws of life, in spite of variation in form and appearance, is not 

 one of the least benefits which hav^e resulted from the investigations of 

 modern science. 



At the point where calorification results from chemical phenomena 

 accompanying nutrition and respiration a close dependence springs up 

 between it and the process of alimentation. This dependence clearly 

 exists. The phenomena of alimentation are in consequence of the in- 

 troduction of food into the organism in such a manner that it can be 

 assimilated, portions of it immediately, and that which remains after 

 it has undergone chemical modifications. To the former category va- 

 rious salts and water belong; to the latter, organic compounds, flesh, 

 fruits, vegetables, milk, etc. Where there is a total lack or insufiQ- 

 ciency of alimentation the animal perishes, especially when there is no 

 reserve supply of nutriment in the form of fat. At the same time its 

 temperature falls. This fact has been established by Chossat, who has 

 made an exhaustive study of inanition. Animals deprived of nutri- 

 ment generate less htnit. Their temperature diminishes each day, and 

 finally, at the moment of death, sinks to 10°, 15°, or 20° below the nor- 

 mal medium. The temperature of pigeons, for example, falls from 40° 

 or 42° to 20° or 18°. The same phenomenon exists in the case of man 

 or mammals. It is the same with them as with a boiler when the fur- 

 nace is not fed ; the fire is extinguished and heat disappears. In the 

 vegetable kingdom there is iu all probability a similar occurrence, al- 

 though no visible proof is given of it as far as we know. Experiment 

 in this case is very difficult, but an indirect proof is furnished by the 

 fact, well known to agriculturists and botanists, that the suppression 

 or diminution of such and such mineral salts necessary to vegetable 

 life will result in the deterioration and relative unfruitfuluess of the 

 plant. That which diminishes their vitality and their proportions di- 

 minishes also their initritiou, and as a natural consequence their pro- 

 duction of heat. 



There is therefore between the processes of alimentation and calori- 

 fication a fixed relation, and one can readily determine among the many 

 diflerent kinds of foods those which contribute most towards calorifi- 



