OF BOTTOM HEAT. 109 



vegetation. (See Erster Jahresbericht, dec, am Mittel 

 und Nieder-Rhein, p. 64.) 



Mr. Fintelmann, the king of Prussia's gardener at 

 Potsdam, is celebrated for his success in the difficult 

 art of forcing Cherries, and he has given an account 

 of his practice, (Gard. Mag., vol. iii. p. 64,) in which 

 it appears that the most peculiar feature is the strict 

 attention he pays to the temperature of the roots. He 

 first soaks the roots in water heated by the mixture of 

 equal parts of boiling and cold water ; he afterwards 

 sprinkles the trees with luke-warm water, and he con- 

 tinues to employ it of the same temperature as long as 

 watering is required. 



It seems, indeed, clear, that the success of the Dutch 

 in obtaining an abundance of fresh vegetables, such as 

 Lettuces, during the whole winter, is in part owing to 

 their being able to maintain a gentle bottom heat. No 

 doubt this is connected with the abundant light which 

 their forcing structures admit, and with other causes of 

 considerable importance ; but none of those causes can 

 be suppossed likely, in the absence of the bottom heat, 

 to produce such a result as the Dutch gardeners 

 obtain. 



If it is necessary that the temperature of the soil in 

 which plants grow should be carefully, regulated, and 

 adjusted to their natural habits, it is no less requisite 

 that the water in which aquatics are cultivated should 

 be also brought to a fitting heat. Mr. William Kent 

 succeeded well in making many tropical species flower, 

 by growing them in lead cisterns plunged in a tan -bed, 

 {Hart. Trans., iii. 34, ) in a close heat. In like manner, 



