210 HA HITS- OF PLAXrS. 



It requires, the degree of light which seems necessary, and the kind 

 of exposure, as to winds, whielx appears most favourable. 



Plants vary much in their susceptibility of naturalization. T he- 

 horse-chestnut, which is now common in the middle and northern 

 United States, was originally brought from the tropical regions. Ins 

 these regions, however, it usually grows in grounds somewhat above 

 the level of the sea, and therefore its habit, as to temperature, ren- 

 ders it in some degree fitted for more northern countries. Orange 

 and lemon-trees cannot be brought to bear the roughness of our cli- 

 mate, without some protection. 



In many cases, perennial plants by this change of climate are con- 

 veited into annual o-nes ; as if fearing the inclemenciesof a cold win- 

 ter, they pass through their soccessive stages of existence with ra- 

 pidity, and accomplish in one summer what fliey had been accus- 

 tomed to require years to perform. The nasturtion was originally a- 

 perennial shrub, flourishing^ without cultivation on the banks of the 

 Peruvian streams ; yet, transferred to this country, it is an annual 

 herbaceous plant, which completes its term of existence in a few 

 months. 



The acclimating of some plants is with difficulty accomplished^ 

 and it is by slow removals that they can be made to grow in foreign 

 situations. Rice by a slow progress has advanced from Carolina to 

 Virginia, and it is now cultivated in New Jersey. The habits of In- 

 dian com, aided by climate and culture, have suffered a still mor© 

 remarkable change. After having: been for several years raised iii 

 Canada, it arrives to perfection in a few weeks, and on that account 

 is employed by us as an early corn ; but that which has been long 

 cultivated in Virginia, will not ripen in a New England summer ; yet 

 originally, the early corn of Canada and that of' Virginia were the 

 same, both in habit and othes properties. 



While merely ornamental or curious plants can with difficulty be 

 made to vegetate freely in foreign situations, the vegetables most 

 useful to man are disseminated and cultivated. The delicate exo^ 

 tic flowers often disappoint our expectations ; but the wheat, the po- 

 tato, and corn, which are also exotics, seldom are withheld from the 

 labour of the husbandman. 



Thus should earthly parents, imitating their " Father in heaven," 

 first provide their children with what is iisefid both for body and 

 mind, leaving the ornamental to be bestowed or not, as circumstan- 

 ces may render proper. 



Agents ichich affect the growth of Plants. 



Of the various substances by which vegetables are nourished, wa- 

 ter is thought the most important. Some plants grow and mature 

 with their roots immersed in water, without any soil; most of the 

 marine plants are of this description. 



Atmospheric air is necessary to the health and vigour of plants; if 

 a plant is placed under a glass into which no air can enter, it withers 

 and dies. 



Most plants are found by analysis to contain a certain portion of 

 salts^ such as nitre, and muriate of soda,* or common salt. It ap- 

 pears that the root absorbs them from the soil by which it is nour- 

 ished. 



* According to modern chemistry, chloride of sodium. 



Plants vary in stisceptibility of natiirahzation— Some plants change from perenniai 

 \o anmial — Rice and Indian-corn— Agents that affect the growth of plants— Water — 



A .inospheric air— SaUs. 



