UTENSILS USED IN HORTICULTURE. 145 



so as to isolate them, and of course the pots which stand on them, from 

 wingless insects, snails, worms, &c. Fig. 59 shows one of these utensils, 

 which might easily be substituted by a common saucer and whelmed pot. 

 An annular saucer, fig. 60, for containing water, is used either for protecting 

 plants in pots or plants hi the open ground ; and if lime-water or salt-water 

 is used, they will prove a very effectual protection from snails, slugs, 

 wood-lice, ants, and other creeping wingless insects. A very ingenious 

 substitute for this utensil has lately been invented by Mr. Walker, of 

 Hull. It is founded on the galvanic principle of alternate plates of zinc 

 and copper producing a galvanic shock, and is therefore called the 

 Galvanic Protector. Take slips of zinc four or five inches in breadth, in 

 order to inclose the plant or bed to be protected, as with a hoop ; but in 

 addition to the mere rim or frame of zinc, rivet to it, near the upper edge, 

 a strip of sheet-copper one inch broad, turning down the zinc over this so 

 as to form a rim, composed of zinc, copper, and zinc. The deterring effect is 

 produced by the galvanic action of the two metals ; and thus, when the snail 

 or slug creeps up the rim of zinc, it receives a galvanic shock as soon as its 

 horns or head touch the part where the copper is inclosed, causing it to recoil 

 or turn back. A more beautiful application of science in the case of deter- 

 ring insects is rarely to be met with, and it will not cost more than Qd. a lineal 

 foot. (Gard. Chron. vol. i. p. 115, and 165; and Gard. Mag. 1841.) 



423. Rectangular boxes for growing plants are commonly formed of wood, 

 but sometimes slate is substituted. Wood, however, as a better non-con- 

 ductor both of heat and moisture, deserves the preference. A neat and 

 most convenient plant-box was invented by Mr. M'Intosh, fig. 61, and 



used by him for growing orange-trees. 

 It differs from the orange-boxes used 

 in the gardens about Paris in having 

 the sides tapered a little, and also in 

 having all the sides moveable. Two 

 of the sides are attached to the bottom 

 of the box by hinges, and are kept in 

 their places by iron bars hooked at each 

 end, which slip into hasps fixed in the 

 sides, as shown in the figure ; the other 

 sides, which are not hinged, lift out at 

 leisure, being kept in their places at 

 Fig. 61. Plant-box. bottom by two iron studs, which drop 



into holes in the bottom. These boxes afford greater facilities than the French 

 orange-boxes for the gardener to take them to pieces, without disturbing the 

 trees, whenever he wishes to examine or prune their roots, to see whether 

 they are in a proper state, as regards moisture, or to remove the old, and put 

 hi fresh soil. The inside of these boxes can also be painted, or covered with 

 pitch, as often as may be judged necessary ; which will of course make them 

 much more durable, and the trees may be removed from one box to another 

 with the greater facility. 



424. Wooden tubs are very commonly made use of on the Continent to grow 

 orange-trees, and they are made of different heights and diameters from one 

 to two or three feet. When the roots of the trees are to be examined, or 

 old soil to be removed and fresh soil added, the cooper is sent for, who sepa- 

 rates the staves, and after the gardener has finished his operations, replaces 



