128 



Our system is always to keep the surface of the 

 soil and plunging materials pretty moist, by frequent 

 sy ringings in fervid weather ; and by keeping a quan- 

 tity of rough lumps of charcoal spread about the sur- 

 face, a genial vapour is at all times in circulation, 

 particularly in sunny days, when it is most requisite. 



We will now furnish some directions for the 

 management of some of the sources from whence 

 bottom heat is usually obtained. 



Tanner s Bark, if employed as a source of heat for 

 the pine apple, requires very constant attention to 

 preserve it from injurious vicissitudes of temperature. 

 Fresh bark should always be had for this purpose, not 

 more than a week or ten days, or at the most three 

 weeks, out of the tan-pit. 



Tan, when it has undergone a good and regular 

 fermentation, for a period of about four weeks, if 

 kept from excessive moisture, has a sort of charm for 

 the growth of all plants that are natives of warm cli- 

 mates. When it is to be used as bottom heat, it will 

 be advisable to keep it in a dry shed while in a state 

 of fermentation ; and it being full of moisture when 

 taken out of the tan vats, it will require no additional 

 moisture while in a state of preparation for the 

 growth of pine apples, or any other exotic. The 

 time required to bring it into a sweet state will be 

 about four weeks. Three or four turnings will be 

 necessary ; and during the operations of turning, let 



