500 CULTURE OF THE CUCUMBER IN A DUNG-BED. 



bottom heat ought to be, and cold should be carefully guarded against 

 immediately afterwards, by giving air sparingly, so as not to promote too 

 rapid an evaporation. If the temperature of the bed, with the dung in a 

 dry mouldy state, does not exceed 75, the plants will not be destroyed, 

 more especially if air is given night and day to allow the impurities which 

 rise from dung in such a state to pass off into the atmosphere. " Too much 

 bottom-heat," Mr. Mills observes, " there cannot be, if it is moist and 

 sweet." It will not destroy the roots of the plants, provided no more of 

 the surface of the bed is covered with soil than the space occupied by the 

 hillocks. The heat of the dung will then escape freely, and as the roots in 

 the hillocks are above the dung they will not easily be injured by pure heat. 

 Some persons form the hills on a flat basket, so as to be able to remove them 

 if the bed should be overheated, or should become in other respects unsuit- 

 able : others, as Mr. Smith, place the plants over an air-chamber or vault, 

 the sides of which are formed with dung ; while Mr. Duncan places his 

 plants over a well formed in his dung-bed, two feet in diameter, under the 

 centre of each light, communicating with exterior linings or casings, by 

 transverse trenches. 



1061. Linings of cucumber beds and their management. The following 

 directions by Mr. Mills are the most complete that we know of on the 

 subject of dung- linings ; and they may be studied with advantage with 

 respect to the use and management of exterior casings or linings of fer- 

 mented matters generally : " Linings should be turned over once in 8 or 10 

 da} r s, to keep them in a regular state of fermentation, especially from 

 November to February, inclusive. They should not, however, be all 

 turned at once ; and if the back lining is turned, I will suppose, on the first 

 or second, the frontage should be done on the fifth or sixth ; so that one half 

 is turned in five days. The ends will not require turning so often, provided 

 the heat keeps up to what is necessary, according to the season. To dry the 

 inside of the frame in December, January, and February, let the linings be 

 4 inches or 5 inches above the level of the surface of the bed, which will be 

 sufficient ; in March and April they may be lowered in proportion to the 

 increased power of the sun's heat. It may appear unnecessary to some 

 persons to have the linings turned so often ; but I beg to remark, that on 

 the lively heat emanating from them the well-doing of the plants depends, 

 especially when the heat of the bed begins to decline ; and in proportion as 

 attention is bestowed on them, will be the success of the cultivator. If they 

 are allowed to lie undisturbed until they heat themselves dry, they become 

 useless ; and the same effect is produced if they get overcharged with mois- 

 ture. In both cases, if not rendered entirely useless, they will take so long 

 a time to recover their heat, as to render them next to valueless ; for where 

 a warmth is requisite, in addition to that of the bed, the plants may be lost 

 in the interval between the turning and re-rising of the heat. During the 

 operation of turning, should there appear any part too much decayed, let it 

 be removed, and its place filled with fresh linings, which should be put on 

 the top of the old, in order to draw up the heat from it, and to keep up a 

 good warmth round the frame ; besides, when the new linings are above th e 

 bed, there will be no danger of their rank steam getting to the plants. 

 When the linings are again turned, the fresh manure applied must continue 

 at the top ; and, if necessary, some more must be added to it, in order that 

 the right height may be preserved. It must, however, be observed that the 



