190 PEINCIPLES OF GAEDEXING. [CH. VI. 



gas inspired by one volume of the flowers and 

 leaves : 



Cheirantlius incanus, 6 p.m. . . 



Ditto double-flowered 



Poljantlies tuberosa, 9 a.m. . 



Ditto double-flowered 



TropEeolum majus, 9 a.m. . . . 



Ditto double-flowered 



Datura arborea, 10 a.m. 

 Passiflora serratifolia, 8 a.m. . 



Daucus cai'ota, 6 p.m 



Hibiscus speciosus, 7 a.m. 

 Hypericum calicinum, 8 a.m. . 

 Cucurbitamelo-pepo, male flowers, 



7 A.M 



Ditto female ditto, 7 a.m. 

 Lilium candidum, 1 1 a.:m. . 



Typha latifolia, 9 a.m 9.8 . 4.25 



Fagus castanea, 4 p.m 9.1 . 8.] 



As the flowers inhale more oxygen than the leaves, 

 so do they exhale more carbonic acid than these or- 

 gans ; and, unlike leaves, they pour it forth not only 

 during the night, but in the sun-light — at least, 

 Dr. Priestley, Dr. Ingenhouz, and M. Saussure found 

 this was done by the rose, marigold, and honey- 

 suckle. 



It is upon the oxygen combined with their paren- 



