55 



nc air, one of which was inverted over mercury, and 

 the other over water. Each of the pots was sur- 

 rounded by a quantity of powdered lime, spread on 

 the board by which it was supported. The leaves of 

 the plants in the mercurial jar continued green for 

 several days, and became at length very much 

 curled, but the plants themselves had not increased 

 in height ; and when withdrawn from the jar on 

 the sixth day, their leaves were dry to the feel, 

 crumbled between the fingers, and were still very 

 green. The jar, during the greater part of the time, 

 remained dry and transparent ; the lime was much 

 increased in bulk ; and the mercury had risen consi- 

 derably into the jar. In the other jar, the water, by 

 the second day, had risen so as to moisten the lime, 

 and its whole inside was quite bedewed with mois- 

 ture, which appearance it continued to exhibit 

 through the whole period of the experiment. The 

 leaves of the plants did not continue dry or green as 

 in the former case, but assumed a yellowish appear- 

 ance, and, by the fifth day, the plant had increased 

 an inch and a half in length, the leaves becoming 

 still paler and more yellow ; and when withdrawn 

 from the jar, on the sixth day, they were quite 

 moist to the feel. From these experiments, it ap- 

 pears, that lime, placed in jars with growing plants, 

 abstracts their moisture, and thereby checks their 

 growth ; but that if the lime be previously moisten- 

 ed, the growth of the plants is not checked, and their 

 moisture is as great as usual. But water is as ne- 

 cessary to vegetation (23.) as air ; and, therefore, 

 granting unto lime the power of attracting carbonic 

 ucid as well as water, the death of the plants in M ? 



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