PRU 



PRU 



as the flour of wheat into starch, ' 

 sugar, gum, fibrin, gluten, albumen. 

 These are also called jiroxnnulc prin- 

 ciples. This kind of analysis is made 

 by means of solvents, as alcohol, 

 ether, water, potash, and acids : it is 

 coarse and unsatisfactory. 



PRUNING. "The art of cutting 

 off parts of plants, and more espe- 

 cially of trees and shrubs, with a 

 view to strengthening those which 

 remain, or of bringing the tree or 

 plant into particular forms, calcula- 

 ted to increase particular products. 

 Pruning, therefore, varies according 

 to the kind of plant or tree to be 

 pruned, and according to the object 

 in view. In the case of forest- 

 trees, the general object of pruning 

 is to increase the quantity of tim- 

 ber in llie trunk by diminishing the 

 side branches, commencing at the 

 lower part of the tree when it is 

 quite young, and gradually advancing 

 upward as the tree increases in 

 growth. In the case of hedges, the 

 object is to produce a dense mass 

 from the ground upward, which is ef- 

 fected by shortening the side branch- 

 es. In the case of pruning trees 

 which are cultivated for the sake of 

 their fruit or blossoms, the object is 

 to thin out the branches so as to ad- 

 mit tlie light and air more freely to 

 their leaves and blossoms, and to 

 concentrate and increase the nour- 

 ishment 10 the branches which re- 

 main. In the case of trees or shrubs 

 cultivated for the beauty of their 

 shapes, whether natural or artificial, 

 the object of pruning is to dejirive the 

 trees or shrubs of all those branches 

 which deviate from or interfere with 

 the natural shape, or with the form 

 which is intended to be produced by 

 art. In pruning with a view to pro- 

 duce fruit, it is necessary to know on 

 what description of l)ranches and 

 buds the fruit is produced. In some 

 trees, as in the peach, it is generally 

 produced on the wood of the prece- 

 ding year ; in others, as in the apple 

 and pear, it is generally produced on 

 wood of two years' growth ; and in 

 the vine it is produced on shoots of 

 the current year. The general efTect 

 G44 



of pruning on plants is to increase 

 their longevity ; since the tendency 

 of all vegetables is to exhaust them- 

 selves, and, consequently, to shorten 

 their duration, by the production of 

 seeds. In the operation of pruning, 

 the shoots are cut off close to the 

 buds, or at a distance from them not 

 greater than the diameter of the 

 branch to be cut off; because, with- 

 out the near proximity of a bud, the 

 wounds will not heal over. In shoots 

 which produce their buds alternately, 

 the cut is made at the back of the bud, 

 sloping from it, so as that it may be 

 readily covered by bark in the same 

 or in the following year. This is 

 readily done with a pruning knife, by 

 a slanting cut, made at an angle of 

 45^ with the direction of the branch ; 

 but in the case of branches where 

 the buds are produced opposite each 

 other, either one bud must be sacri- 

 ficed, or the branch must be cut off at 

 right angles to its line of direction, 

 and is more conveniently done by the 

 pruning shears. The operation of 

 pruning may, in many cases, be su- 

 perseded by rubbing off, or pinching 

 out the leaf-buds, so as to prevent 

 superfluous shoots from being pro- 

 duced.'' — {Luidley.) 



Where bleeding occurs in summer 

 pruning, the stem should be first 

 pinched by the thumb and finger, to 

 destroy the tissues, and removed 

 when dead : in this way vines and 

 figs may be pruned at any time. The 

 best time for pruning trees is in June 

 and July, when the wounds heal 

 readilv 



PRUNING KNIFE. '■ A knife the 

 blade of which has a straight edge, 

 formed of well-tempered steel, and 

 of no great breadth, with a narrow 

 point, in order that it may be more 

 readily introduced among crowded 

 branches. Formerl}', pruning-knives 

 were hooked at the point ; but the 

 cuts made by such knives had a ten- 

 dency to crush the shoot, and leave 

 a rough section, more readily injured 

 by the air and water, and less likely 

 to be speedily healed over. Such 

 knives, when of a large size, were 

 called pruning hooks. 



