SECT. II. GASES. 6l 



whose experiments appear to have given a similar 

 result ; contradicted, however, by the result of the 

 experiments of Senebier, Woodhouse, and Saussure, 

 on the same subject. 



Branches of Populus nigra and Satix alba, 

 whose leaf-buds were just ready to open, were in- 

 troduced by Saussure into an atmosphere of ni- 

 trogene both in the shade and sun. They effected 

 no farther developement of parts, but were found 

 to be in a state of putrefaction after a period of five 

 days ; but in an atmosphere of common air they 

 readily effected their developement, and continued 

 to vegetate for many weeks. Roses and Lilies ga- 

 thered two or three hours before their expansion, 

 and treated in the same manner, gave similar 

 results. 



It must be admitted, however, that many plants Though 

 will continue to vegetate for a time in an atmosphere p^ s will 

 of nitrogene gas, when their leaves have been pre- fo 

 viously developed ; but they are such plants only 

 as present a great extent of surface, and consume 

 but little oxygene in the shade. A plant of the 

 Cactus Opuntia, nourished with water and placed 

 in an atmosphere of nitrogene gas exposed to the 

 influence of the sun, was found capable of sup- 

 porting vegetation for the space of three weeks ; 

 but it was greatly injured by the experiment, and 

 in the shade it lived only five days. A plant of 

 the Scdum telephium when treated in the above 

 * Sur la Veg. chap, vi. sect. ii. 



