UTEXSILS USED L\ HORTICULTURE. 103 



lately been invented by Mr. Walker, of Hull It is founded on the 

 galvanic principle of alternate plates of zinc and copper producing an 

 electric shock, and is therefore called the Galvanic Protector. Take 

 slips of zinc four or five inches in breadth, in order to enclose 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 pro- 

 duced 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 enclosed, 

 causing it to recoil or turn back. A more beautiful application of 

 science in the case of deterring insects is rarely to be met with, and it 

 will not cost more than 6d. a linear foot. (* Gard. Chron.,' vol. i. pp. 

 115 and 165 ; and 4 Gard. Mag.,' 1841.) 



Rectangular boxes for growing plants are commonly formed of wood, 

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

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

 and most convenient plant-box was invented by Mr. M'Intosh, fig. 69, 

 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 Plant-box. 



places at 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 in 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 greater facility. 



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

 grow orange-trees, and they are made of different heights and diame- 

 ters 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 separates the staves, and after the gardener has finished 

 his operations, replaces them again and fixes the hoops. In the warm 



