286 Centre Bed hi a Hot-house 



of great depth ; instead of occupying high sites, occupies the 

 lowest; instead of being well drained, is usually saturated 

 with water to the very roots of the herbage it bears ; instead 

 of a draining stony subsoil, stones are almost totally absent 

 from it, and the subsoil is a water-holding clay. Although, 

 like heath-mould, the surface soil exhibits spongy masses of 

 fibres, it lacks the sand which prevails in heath-mould; 

 and, when wet, is not friable, but oozy and soapy. Heath- 

 mould, by means of its dry nature, its vegetable fibre, and 

 its sand, is disposed to continue light, open, and porous : peat, 

 from its muddy adhesive nature, the great rapidity with which 

 vegetable fibre decays in it, its lack of sand, or from other 

 causes, speedily subsides into a dense, inert, coagulate mass. 

 While heath-mould is most important to the gardener, peat 

 is not only totally unfit for, but even inimical to, most of the 

 purposes of floriculture ; although, as nothing in nature is 

 left unused, it is the very soil in which willows, many grasses, 

 the rushes, the sedges, and similar families, thrive and 

 luxuriate. , 



If my brother gardeners admit the distinction I have 

 striven to show, I hope they will adopt it. 



I am, Sir, &c. 

 Feb. 16. 1831. J. D. 



Art. X. An Account of the Application of hot Water to heating 

 the centre Bed in a Hot-house, in lieu of Tan. By J. T. Alcock, 

 Esq., of Mount Hill, Caermarthenshire. 



Sir, 



According to your desire, I send you a more detailed 

 account of the application of hot water to heating the central 

 bed in a hot-house, in lieu of tan, or any other fermenting 

 matter. 



From the reservoir {Jig. 51. a) I branched a small deliver- 

 ing pipe {b) 1 f in. in diameter, which was continued to the 

 opposite angle of the bed, where it formed a dip of 10 in. at 

 c, and returned to the reservoir at d. I then constructed 

 laterals of f in. leaden pipe {e), which were soldered into 

 the delivering branch at 8 in. apart, and, having crossed the 

 bed, dipped into the returning branch as at c. The space un- 

 derneath was previously filled up with small stones and gravel, 

 with about 2 in. of sand on the surface, on which the pipes 

 were placed. The whole was then covered with sand, about 

 4 in. deep, and it worked admirably. 



