THE VEGETABLE KINGDOM. 419 



filled, were hermetically sealed by fusion and deposited in 

 the sarcophagus with the dead. The lachrymal vase 

 having been broken and its contents analyzed, the great 

 chemist found that the air was of exactly the same com- 

 position as the fluid which we respire now-a-days. 



M. Lacreze-Fossat was enabled, by means of delicate 

 experiments, to determine the proportion of respirable 

 gas discharged into the atmosphere by certain plants. 

 This observer noticed that in tAvelve hours the under 

 surface of the large floating leaves which the yellow 

 water-lily {Nym.jjhcea lutea) spreads out on our rivers, pro- 

 duced 17 centilitres (10 '37476 cubic inches) of oxygen. 

 And, according to him, a single specimen of this plant, 

 composed of fifteen leaves, in five months exhaled into the 

 atmosphere 535 litres of this gas (1177 gallons).^ 



How much then must be produced in a single season 

 by a large tree, the respiratory surface of which is of such 

 a size compared to that of the aquatic plant.- 



purity of the air), even supposing that vegetable life remained annihilated during 

 all that time. Thus the proportion of oxygen the air contains is guaranteed 

 for many ages, even entirely excluding the action of plants. Nevertheless these 

 incessantly return to it as much oxygen as it loses, and perhaps more, for plants 

 also exist as much at the expense of the carbonic acid furnished by volcanoes 

 as at that of the acid expired by animals. — Dumas, Essai de Statique Chimique 

 des Etres Organues. Paris, 1842, p. 18. 



^ M. Lechartier has communicated some facts of interest with regard to the 

 absorption of air by water-plants. The gas contained in the stem of the water- 

 lily is richer in carbonic acid than the gas contained in the petiole. The general 

 conclusion would seem to be that the gases are absorbed by the deeper parts and 

 exhaled by the more superficial tissues.— Co«!joi!e.s Rendus, t. Ixv. No. 2G.— Tr. 



2 In the number of the remarkalile phenomena of vegetation we may mention 

 the property possessed by some plants, and especially the Chara {Cham fmgilis), 

 of decomposing the sulphates found in the water and transforming the sulphur 

 mto sulphuretted hydrogen, thus giving origin to the so-railed sulphureous 

 mineral waters. It was from not having known tliis fact, that those who 

 unseasonably removed the putrid hydro-sulphuretted mud from particular 

 marshes, dried up the mineral springs which were a source of wealth to certain 

 bathing establishments. 



