with regard to Temperature. 1 9 



duce finally the result which would be the effect of an adherence 

 to the simple dictates of nature. 



Almost every gardener is aware that, for all practical pur- 

 poses, well-ripened, firm, short-jointed wood is greatly preferable 

 to that which is luxuriant and long-jointed ; and, therefore, as 

 an increase of temperature exerts the same expanding influence 

 upon vegetables as upon other bodies, and as this expansion, in 

 the case of vegetables, is greatly accelerated by their being kept 

 in the shade, and in a humid atmosphere, it follows that the 

 keeping up of a strong moist heat in hot-houses, at night, is the 

 very best means for producing elongation of stem and long- 

 jointed wood. But as it is very doubtful if, in these circum- 

 stances, much valuable substance is added to the plant, as it is 

 only when exposed to the agency of light (so say our most 

 celebrated philosophers) that the process of decomposing car- 

 bonic acid is effected, and the sap receives its final elaboration, 

 so as to become, as it were, the nourishing blood of the plant; 

 it becomes necessary to counteract this tendency to the pro- 

 duction merely of elongation of stem, by preventing the ther- 

 mometer from rising more than a few degrees above the fire- 

 heat standard, by admitting large quantities of air during the 

 day. .By this means the internal is reduced to almost an 

 equality with the external atmosphere, and, by making an im- 

 proper use of artificial heat, the cultivator is under the necessity 

 of depriving himself of the advantages which he might otherwise 

 have derived from the heat of the sun. The tendency of keeping 

 a high temperature at night is to over-stimulate the plants, 

 causing them to expend prematurely their powers of excitability, 

 and, if not counteracted by the means I have referred to, the 

 prejudicial effects soon become apparent. As one instance, I 

 may mention, that last season (1832), it being very desirable to 

 have grapes in a pine stove ripe as soon as possible, no trouble 

 was spared to keep up a high temperature both night and day ; 

 and the consequence was, that, although the vines made pretty 

 good wood, the fruit never was high-flavoured, nor yet well- 

 coloured, and soon became shriveled, or rotted off. As the 

 shriveling of grapes is very much complained of, it may be 

 worth the attention of the gardener to enquire, if, in addition to 

 leaving too much fruit for the strength of the vine, &c, it may 

 not sometimes be owing to the keeping up of a high temperature 

 both night and day ; by which, notwithstanding the accommodating 

 capabilities of plants, their powers of excitability become ex- 

 pended before the fruit has received its due share of nourishment. 

 But the circumstances to which I wish particularly to direct the 

 attention of my "brothers in youth and in trade" is, that, inde- 

 pendently of all our exertions, the grapes, in the pine stove referred 

 to, were not fit to cut above eight days sooner than those in a 



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