26 THE FLOWER GARDEN COMPANION, 



qualities in a certain degree. So tenacious of light, are most 

 kinds of plants, that, when deprived of this stimulant, they 

 begin to assume a yellow appearance, and in time, when 

 fully excluded, they turn to a clear white : it is also obvious, 

 that when they again receive a full share of stimulating influ- 

 ence, they resume their wonted appearance. 



I shall conclude this subject by impressing on the mind of 

 my readers, the utility of light to plants generally, and es- 

 pecially in frames and green-houses, in the early part of the 

 season, when every opportunity should be taken to admit it. 

 Let them also remember that in winter, owing to the short 

 days, the due quantity of light cannot be given ; this should 

 always be taken into consideration by the cultivator. 



ART. 4. Heat. 



It is very evident to the most common observer, that a cer- 

 tain degree of heat is required by all plants to cause them to 

 grow, in a healthy, vigorous state. As we find that plants 

 similarly situated, though natives, do not all vegetate at the 

 same time : so also seeds require a different temperature of 

 heat, to cause them to vegetate freely ; hence it will be seen 

 that all kinds of native seeds vegetate early in the spring, and 

 many exotics, as the Stock-gilliflower, Candy-tuft, and the 

 like hardy kinds : while the more tender varieties, as the 

 Balsam, Globe Amaranth, Cypress vine, and the like, must 

 be deferred until a warmer season. The same affinity is 

 also observable in the circulation of sap in trees, as they are 

 seen to put out their foliage and to commence in growth at 

 different times in the same location. 



Heat may be considered under two heads, namely, sun 

 heat, or natural; and artificial, as that applied by fire, fermen- 

 tation and the like. Sun heat may be in all cases considered 

 as natural to plants, although in many cases where plants are 

 placed in very moist situations they are drawn weak when it 

 acts too powerfully on them after much wet, and in such 

 cases the leaves are seen to flag and shrivel up. Fire heat 



