246 On a Method of Forcing Vines and Nectarines, 



principally, if not entirely, cow-dung, which is laid upon the 

 floor of his house, extending entirely from end to end, and 

 in width about six or seven feet, leaving only a pathway 

 between it and the back wall of the house ; the dung-bed is 

 represented in figure B of the section. 



The dung being all new at the beginning, a profuse steam 

 arises with the first heat, which, in this stage of the process is 

 found to be beneficial in destroying the ova of insects, as well 

 as transfusing a wholesome moisture over the yet leafless 

 branches; but which would prove injurious, if permitted to rise 

 in so great a quantity when the leaves have pushed forth. In a 

 few days the violence of the steam abates as the buds open, 

 and in the course of a fortnight the heat begins to diminish ; 

 it then becomes necessary to carry in a small addition of 

 fresh dung, laying it in the bottom, and covering it over with 

 the old dung fresh forked up : this produces a renovated 

 heat, and a moderate exhalation of moist vapour. In this 

 manner the heat is kept up throughout the season, the fresh 

 supply of dung being constantly laid at the bottom, in order 

 to smother the steam, or rather to moderate the quantity of 

 exhalation; for it must always be remembered, that Mr. 

 French attaches great virtue to the supply of a reasonable 

 portion of the vapour. The quantity of new dung to be in- 

 troduced at each turning, must be regulated by the greater 

 or smaller degree of heat that is found in the house, as the 

 season or other circumstances appear to require it. The 

 temperature kept up is pretty regular, being from 65 to 70 

 degrees. 



Mr. French contends, that the moist vapour which is 

 transfused through the house is essentially beneficial, not only 



