LECT. II.] VITAL FUNCTIONS OF PLANTS^ 61 



then, as is the case with animals, no further change 

 on the atmosphere is produced than is occasioned 

 by the process of decomposition. 



Connected with this function of plants, and 

 depending on the same cause, is that power which 

 they possess in common with animals, of resisting 

 to a certain degree the alternations of temperature 

 of the atmosphere. Every animal and every 

 vegetable has a peculiar innate temperature, inde- 

 pendent of that of the surrounding air. The 

 power of the animal body in preserving this degree 

 in very low temperatures is truly astonishing; 

 nor is its power less in resisting the effects of great 

 heat. Dr. Fordyce, who was the first person that 

 accurately remarked this last property of animal 

 life in the human body, made several experiments 

 in heated rooms, assisted by Dr. Blagden, Sir Jo- 

 seph Banks, and some other gentlemen. In these 

 the rooms were heated to a degree far exceeding 

 any that can possibly take place in the natural at- 

 mosphere in any climate ; and as a clear proof that 

 it was the living principle alone which enabled 

 them to resist such extraordinary degrees of tem- 

 perature ; in one of the experiments, a beef-steak, 

 placed in the heated room with the persons trying 

 the experiment, was roasted in forty-seven minutes. 

 The power possessed by living vegetables of resist- 

 ing the changes of temperature of the external air, 

 cannot be supposed to be so great as that of ani- 



