TEMPERA TURE. 377 



heat was obtained at or shortly after the opening 

 of the spathe, or the climax of flowering. Tempe- 

 ratures ascertained at different periods of the day 

 would necessarily be influenced more by the con- 

 dition of the flowers than by the precise hour. This 

 will account for the maximum being fixed at different 

 hours by different observers. Subsequent experi- 

 ments conducted by M. Garreau at Lille demon- 

 strated the great consumption of oxygen which 

 accompanied the elevation of heat and its propor- 

 tionate increase. When the mean heat was seven 

 degrees, sixteen volumes of oxygen were consumed 

 per hour ; when the mean heat rose to twelve, the 

 consumption of oxygen increased to twenty-one 

 volumes ; and when the mean heat had attained 

 seventeen and a half, the volumes of oxygen con- 

 sumed exceeded twenty-seven. The quantity of 

 carbonic acid evolved is in direct proportion to the 

 oxygen absorbed, and the degree of chemical action 

 which takes place determines the amount of heat. 



We shall be prepared to concede that, after all, it 

 is not so remarkable that here and there we meet 

 with records of an elevation of temperature at the 

 time of flowering, in plants where the natural condi- 

 tions are favourable, as that these records are not 

 more numerous and explicit. Mr. N. E. Brown states 

 that on one occasion the living spadix of Philoden- 

 dron Williamsii, which had flowered at Kew, was 



