the Nitrogenous Matter of Plants. 



121 



evident that a well-marked relation subsists between the quantity 

 of carbon consumed and the elevation of temperature produced. 

 These results, it is true, are deficient in that degree of precision 

 that researches of this nature should possess ; for it is to be 

 regretted that De Saussure and Berard have neglected to indi- 

 cate exactly, as Dutrochet has done, the mean temperature at 

 which the observations have been conducted. Notwithstanding 

 this omission, however, the relations pointed out are real. 



The following Table, conveying the results of our own obser- 

 vations, moreover shows the relations subsisting between the 

 oxygen consumed and the degree of heat emanatiug from its 

 union with the carbon in the plant : — 



Respiration of the spadix of Arum italicum, at the temperature 

 of 20° Cent., and during the period of its sexual activity. 



It may be objected that the production of carbonic acid 

 within the vegetable tissue, and that of the caloric which results 

 from it, are the consequences of a purely chemical action, and 

 not of a physiological process. But if we consider that the 

 researches of Theodore de Saussure, of Berard, and of Dutrochet 

 have been made on living organs in process of growth, that 

 parts of plants when broken or bruised up cease to form car- 

 bonic acid, as the experiments of De Saussure, Fremy, and our- 

 selves demonstrate, and, lastly, that the death of the tissue, as 

 evidenced by the persistent loss of movement of the nitrogenous 

 living material, involves the cessation of the development of this 

 gas, the conclusion is inevitable that its formation is the conse- 

 quence of a vital act. "What, in conclusion, along with the 

 causes just enumerated, convinces us that the animal respiration 



