51 
ing part of the air, to the sun, for several hours, and 
found it, on examination, to be still more deteriora- 
ted. The flowers of honeysuckle produced similar 
effects, as did many others which he submitted to 
experiment * ; so that flowers equally deteriorate 
the air in sunshine and in the shade. 
272. In his experiments on flowers, M. de Saus- 
sure found that none, not even those of aquatic 
plants, could be developed in nitrogen gas ; that the 
buds just ready to expand were suddenly checked, 
and those already developed speedily died. He con- 
siders flowers to displace in part the air that sur- 
rounds them, and to replace, by carbonic acid, the 
portion of oxygen which they consume. Those 
which are recently gathered, and confined in atmos- 
pheric air, do not sensibly alter its volume. The 
flowers which he employed did not suffer during the 
experiments ; they had not lost their form or fresh- 
ness, and many, which were only in bud, became 
fully expanded. The petals consumed more oxygen 
in sunshine than in the shade ; but he tried in vain 
to excite detonation in oxygen gas, in which he had 
caused bunches of fraxinella to vegetate for eight 
days ; and he thinks, therefore, that the inflammation, 
which may be excited in the atmosphere of this, and 
of some other plants, is owing to the combustion of 
an essential oil, and not' to that of hydrogen gas f. 
273. The changes thus induced on the air by the 
* Exper. sur les Veget. t. i. p. 270, 
t Researches. &c. p. 125, 129- 
D2 
