GENERAL INDEX. 725 



advantages of maintaining a high temperature in hot houses during the day, and a 

 low one during the night, 397 ; mode of fixing canvas shades to, 175 ; on sup- 

 plying water to plants in, 220. 



Hot water, various modes of heating plant structures by, 201 ; on the size and best form 

 of pipes, 204 ; the situation the pipes should be placed in, 205 ; size of boiler, 

 207 ; rain-water should be used forheating by, 213 ; open gutters for circulating, 214 



Hybrid plants, the number of useful and beautiful ones in cultivation, 7 



Hyssop, its use, &c., 694 



Implements of horticulture, 127; the principles on which they are constructed, 128 

 Inarching, uses and principles of, 297 ; mode of performing side and terminal, 298 

 Indian Fig, culture of, 612 

 Insects, their nature and classification, 99 ; transformation of, 101 ; food of, 102; 



distribution and habits of, 104 ; uses of, 105; means contrived by nature to limit 



the multiplication of, 105; enemies of, 106; means of destroying them, 108; 



articles required for destroying, 170 

 Instruments used in horticulture knives, 137 ; asparagus knife, hedge bills, 138 ; 



saws, pruning chisels, shears, 139 ; axe, verge and grass shears, scythes, 140 ; 



various others, 141 

 Iron, in the form of an hydrate, injurious to vegetation, 48 ; roofs, contraction 



and expansion of, 193 



Jerusalem Artichoke, culture of, 646 



Kidney-bean, selection of varieties of the dwarf species, and their culture, 636 ; 

 culture of the twining sorts, 636 ; particulars of the mode of forcing, 520 



Kitchen-garden, its situation, arrangement, extent, and soil, 416 ; should be well 

 drained, trenched, and levelled, 417 ; accompaniments to a, 418 ; plans of two, 

 419, 421 ; systems of cropping the, 435 ; general proportion of crops for one, 

 434 ; general management of, 434 ; seed required for a garden of H acres, 435 



Ladder, description of a folding one for hothouses, 168 



Lamb's Lettuce, see Corn Salad 



Lavender, culture of, 693 



Layering, operation of, 272 ; soil necessary for, 277 



Layers, the principles of propagation by, 272 ; the time they require to produce 

 roots, 277 



Leaves, the developement of explained, 22 ; of endogenous plants should be preserved 

 uninjured during their period of growth, 10 ; necessary to the existence of the 

 plant, 32 ; principles of propagation by, 266 ; conditions required for the rooting 

 of, 267 ; plants usually raised by, 268 ; propagation of bulbs by, 268 ; of plants 

 rooted in charcoal, 269 



Leek, culture of, 663 



Lemon, see Orange 



Lettuce, mode of obtaining full-grown Cabbage Lettuce throughout the winter, 522 ; 

 selection of varieties, and culture of, 674 



Level, its use, 169 



Light, influence of, on the distribution of plants, 41 ; the effect of its absence on 

 plants, 89 ; follows the same laws as heat, 90 ; radiation and transmission of, 90 ; 

 refraction of, 91 ; the importance to plants of perpendicular, 91 ; means of in- 

 creasing the efficiency of, 92 ; heat should be in proportion to, 92 ; absence of, 

 occasionally necessary to some plants, 93 ; light and motion, 699, 700 



Lime, its constituent parts and uses, 48 ; action of on vegetable substances, 62 ; 

 uses of, 63 ; compost, 63 



Lime, see the Orange family, 608 



Liquorice, its use, &c., 694 



Loam, varieties of, 49 



Lodge for under-gardeners described, 225 



Loquat, culture of, 612 



Love-apple, see Tomato 



Machines used in horticulture : wheelbarrow, 153 ; garden syringe, pneumatic 

 hand-engine, 154 ; barrow-engine, 155 ; fumigating bellows, iron fumigating pot, 

 156 ; powdering bellows, mowing-machine, and various others used in gardens, 157 



