Book IV. PREPARATION OF MANURES AND COMPOSTS. 385 



1971. Stable-dung is in the most general use for forming hot-beds, which are masses of 

 this dung after it has undergone its most violent fermentation. These masses are gene- 

 rally in the form of solid parallelograms of magnitude proportioned to the frames which 

 are to be placed on them, the degree of heat required, and the season of the year in which 

 they are formed. 



1972. Tanners bark is> only preferred to dung because the substance which undergoes 

 the process of putrid fermentation requires longer time to decay. Hence it is found 

 useful in the bark-pits of hot-houses, as requiring to be seldomer moved or renewed 

 than dung, or any other known fermentable substance that can be procured in equal 

 quantity. 



1973. Leaves, and especially oak-leaves, come the nearest to bark, and have the addi- 

 tional advantage, that when perfectly rotten like dung, they form a rich mould or excel- 

 lent manure ; whereas rotten tanners' bark is found rather injurious than useful to vege- 

 tation, unless well mixed with lime and earth. 



1 974. Preparation of manures. The object of preparation in these three substances 

 being to get rid of the violent heat which is produced when the fermentation is most 

 powerful ; it is obvious that preparation must consist in facilitating the process. For 

 this purpose, a certain degree of moisture and air in the fermenting bodies are requisite ; 

 and hence the business of the gardener is to turn them over frequently, and apply water 

 when the process appears impeded for want of it, and exclude rain when it seems chilled 

 and impeded by too much water. Recent stable-dung generally requires to lie a month 

 in ridges or beds, and be turned over in that time thrice before it is fit for cucumber-beds 

 of the common construction ; but for M'Phail's hot-beds, or for linings, or for frames 

 with moveable bottoms, three weeks, a fortnight, or less, will suffice ; or no time at all 

 need be given, but the dung formed at once into linings. Tan and leaves require in general 

 a month ; but much depends on the state of the weather, and the season of the year. 

 Fermentation is always most rapid in summer ; and if the materials are spread abroad 

 during frost, it is totally impeded. In winter, the process of preparation generally goes 

 on under cover from the weather, in the back sheds ; which situation is also the best in 

 summer, as full exposure to the sun and wind dries too much the exterior surface ; but 

 where sheds cannot be had, it will go on very well in the open air. A great deal of heat 

 is undoubtedly lost in the process of fermentation ; and some cultivators have recently 

 devised plans to turn it to some account, by fermenting dung in vineries, which are just 

 beginning to be forced, or in vaults under pine-pits or plant-stoves. The latter mode 

 seems one of the best in point of economy, and is capable of being turned to consider- 

 able advantage where common dung-beds are extensively used ; but the most economical 

 plan of any seems to be that of employing only M'Phail's pits, or such as are constructed 

 on similar principles. 



1975. The formation of dung-beds is effected by first marking out the dimensions of 

 the plan, which should be six inches wider on all sides than that of the frame to be placed 

 over it, and then, by successive layers of dung laid on by the fork, raising it to the de- 

 sired height, pressing it gently and equally 375 



throughout. In general, such beds are formed 

 on a level surface ; but Knight's mode {fig. 

 375.) is to form a surface of earth as a basis, 

 which shall incline to the horizon to the ex- 

 tent of fifteen degrees ; on this he forms the 

 dung-bed to the same inclination ; and, finally, 

 the frame, when placed on such a bed, if, as is 

 usual, it be deepest behind, will present its 

 glass at an angle of twenty degrees instead of 

 six or eight, which is undoubtedly of great ad- 

 vantage in the winter season. This seems a 



very desirable improvement where light is an object, which it must be, in a high degree, 

 in the case of the culture of cucumbers and melons, as well as in forcing flowers. 



1976. Ashes are often mixed with the dung of hot-beds, and are supposed to promote 

 the steadiness and duration of their heat ; and at first to revive it, if somewhat decayed. 

 Tan and leaves have also been used for the same purpose ; and it is generally found that 

 about one third of tan and two thirds of dung will form a more durable and less violent 

 heat than a bed wholly of dung. The heat of dung-beds is revived by linings or colla- 

 teral and surrounding walls or banks of fresh dung, the old dung of the bed being pre- 

 viously cut down close to the frame. These linings, as before observed, require less pre- 

 paration than the dung for the beds. The dung-bed being formed, and having stood two 

 or three days with the frame and lights placed over it to protect it from rain, is next to 

 be covered with earth, of quality and in quantity according to the purpose to which it is 

 to be applied. In severe weather, the sides of the bed are often protected by bundles of 

 straw or faggots, which tend to prevent the escape of the heat. 



C c 



