ODOUR OF PLANTS. 7B 



vour its diffusion. This I apprehend to arise more from 

 the favourable action of such moisture upon the health 

 and vigour of the plant itself, thus occasionally promot- 

 ing its odorous secretions, than from the fitness of the 

 atmosphere, so circumstanced, to convey them. Both 

 causes however may operate. A number of flowers 

 which have no scent in the course of the day, smell pow- 

 erfully in an evening, whether the air be moist or dry, or 

 whether they happen to be exposed to it or not. This 

 is the property of some which Linnaeus has elegantly 

 called Jiores tristes, melancholy flowers, belonging to 

 various tribes as discordant as possible, agreeing only 

 in their nocturnal fragrance, which is peculiar, very sim- 

 ilar and exquisitely delicious in all of them, and in the 

 pale yellowish, greenish, or brownish tint of their flow- 

 ers. Among these are Mesembryanthemum noctiflorum, 

 DHL Elth. t. 206, Pelargonium triste^ Cornut. 

 Canad. 110, and several species akin to it, Hesperis 

 tristis, Curt. Mag. t. 730, Cheiranthus tristis, t. 729, 

 Daphne pontica^ Andrews's Repos. t. 73, Crassula 

 odoratissima, t. 26, and many others*. A few more, 

 greatly resembling these in the green hue of their blos- 

 soms, exhale, in the evening chiefly, a most powerful 



* These flowers afford the Poet a new image, which is in- 

 troduced into the following imitation of Martial, and offered here 

 solely for its novelty : 



Go mingle Arabia's gums 



With the spices all India yields. 

 Go crop each young flower as it blooms* 



Go ransack the gardens and field?. 



