106 LATENT HEAT IS LATENT LIGHT. 



excluded, have NO FIBRE, but are watery and unsubstantial, 

 and never reach maturity, or their natural form or beauty. 



In animalization, the three original constituents, oxygen, 

 hydrogen, and nitrogen, are admitted as essential, to which 

 carbon (original or compound) is also added by general 

 consent. ' 



In respect, however, to latent heat becoming evident, by the 

 action of respiration, and the consequent change produced in 

 the blood, without presuming to offer an opinion, I beg to refer 

 to the views of Doctors Black and Crawford, and on the dif- 

 ference between the specific heat of arterial and venous blood, 

 to the facts as ascertained by Doctor John Davy, and that of 

 oxygen gas, and carbonic acid gas, as declared by MM. de la 

 Roche and Berard, with the results of the experiments on the 

 application of artificial respiration kept up in the lungs of a 

 decapitated animal by Mr. Brodie, as recited in the Philoso- 

 phical Transactions, 1812, imputing the production of animal 

 heat to the action of the brain. I shall, without more than 

 reference to opinions emanating from such high authorities, 

 merely submit the following observation, confined to the pro- 

 bable chemical action alone : 



The accumulation of caloric, or heat, appears to arise from 

 the mutual action of the surfaces of the particles or atoms, in 

 changing the position of their poles, and by consequent friction 

 eliciting those electric influences, on the exercise of which every 

 species of decomposition and re-combination depends, and the 

 energy of such caloric must correspond with the attractive force 

 which is exercised. 



The temperature of the lungs is apparently modified by the 

 caloric discharged in the act of expiration of the air inhaled, 

 as well as by the new portions of venous blood, which succeed 

 the ejection of the arterial, to which is to be added the low 

 temperature of the air inspired ; and that in addition to general 

 circulation the decompositions which take place in the other 

 parts of the body, influence the approximation of an equaliza- 



