5G0 



THE PRACTICAL GARDENER. 



may be tliouglit necessary for the purposes required ; and 

 when peculiar circumstances require a speedy augmentation of 

 heat, without displacing the pots, as when the fruit is to be 

 swelled off in the last stage, at which time the roots of the 

 plants will generally be extended into the bed, and would be 

 seriously injured if disturbed, the more decayed tan at the top 

 may be removed in part carefully, and a coat of new tan 

 substituted : this is also often practised when the heat of the 

 bed declines, and the state of the weather, or other circum- 

 stances, prevent a thorough turning over of the whole, ^y hen the 

 tan gets too dry at any time, which it will be apt to do near the 

 flues, water should be poured upon it occasionally between the 

 pots, which will cause a fine moist heat to arise among the 

 plants, which is always desirable in pine-stoves, and will like- 

 wise enable the tan to retain its heat longer than if it were 

 suffered to become dry ; for no vegetable matter will continue 

 in a state of fermentation after the moisture has evaporated. 

 Besides, it will prevent the chance of the dry tan igniting, 

 which is sometimes the case near the flues, admitting that 

 there should be a cavity or space between the bricks that com- 

 pose the flues, and the tan-bed. 



Tan should always be partially dried before put into the 

 bed ; and if kept in an open airy shed, for a week or more 

 before using, so much the better. Heat thus produced will 

 last, with very little trouble, from three to six months, when 

 it is again put into fermentation, by adding a proportion of 

 fresh tan, as stated above. 



Where tan is difficult to be procured, and where oak and 

 other tree-leaves are to be had in plenty, the bed may be 

 composed chiefly of leaves, or a mixture of leaves and stable 

 dunff, usinjr a little tan to surface the bed with, in which to 

 plunge the pots. In using leaves of trees, either alone or 

 mixed with dung, tan, or any other substitute, it is necessary 

 that they be well fermented before they are carried into the 

 pine-house or pit, that the rank heat may be so far extracted 

 from them. They will, in this case, keep to a much more 

 steady heat, and last much longer without renewing. 



Leaves for this purpose should be chiefly composed of oak- 

 leaves J for experience has taught us that they are more dur- 



