ON VEGETABLES. 125 



Emily. These plants, doubtless, require sea-salt ; and 

 yet the vapor which exhales from the sea is perfectly 

 sweet, the clouds which they form are never impregnated 

 with salt; how, therefore, can plants obtain it? 



Mrs. B. Not from the vapor which rises from the 

 sea, but from minute drops of salt water, which are pro- 

 jected into the air by the agitation of the waves, and car- 

 ried by the wind to the shores. Salsola kali, or kelpwort, 

 is a plant of this description : if grown in an inland situ- 

 ation it contains not a particle of soda, the alkali from 

 which it derives its value ; for this can be obtained only 

 from muriate of soda , or sea-salt. During the late war 

 between France and Spain, the French, being greatly 

 distressed for soda, which they had imported chiefly from 

 Spain, attempted to cultivate kelpwort on the hills bor- 

 dering the sea-shore in the south of France. When 

 planted on the southern side of the hill, sloping towards 

 the sea, the crop succeeded perfectly ; and, the price of 

 soda having risen very high, one single harvest repaid 

 the price of the land on which it was raised. But when 

 planted on the north side, where it was not exposed to 

 the briny particles, it failed completely, and the plant 

 contained no other alkali than potash. 



Emily. This explanation solves a difficulty which had 

 often perplexed me. The sea-air is, you know, much rec- 

 ommended to invalids as a tonic ; and the fogs and damp 

 mists, so prevalent on the sea-shore, do not appear to be 

 attended with the debilitating effects produced by inland 

 fogs: this must be doubtless owing to the tonic qualities of 

 the briny particles with which the sea-air is impregnated. 



Caroline. It is true, one can seldom walk out on the 

 sea-shore without one's dress suffering from humidity ; and 

 the salt with which this humidity is loaded is often so 

 strong as to be sensible to the taste. But this prevails 

 only within some few hundred yards of the shore : on 

 rising upon the downs it is no longer perceptible ; and 

 yet it is the air of these downs which is reckoned so par- 

 ticularly invigorating. 



698. How are these effects produced'? 699. What is said of kelp. 

 wort 1 ? 700. Of its growth in France what is said"? 701. What 

 difficulty does Emily say is solved by the account given of the cultivation 

 of kelpwort'? 



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