The other operations of gardening are _pruning_ and _training_, and, as I have already spoken of these when treating of the different trees, I have only to add here that the great art in pruning is to give a clean sloping cut without bruising the bark, as nature will make an effort to cover the wound if the edges of the bark are left in a healthy state. The use of a sloping cut is, to prevent the water from lodging on a wounded part. Trees should never be cut in a hard frost; and as little as possible in summer, as every branch taken off while the plant is in a growing state excites it to make fresh efforts to throw out new shoots. Many persons look over their trees in summer, and rub off all the buds which they think likely to produce useless shoots; and this practice, which is called disbudding, is a very good one, as it prevents the tree from wasting its strength unnecessarily. The principal object to be attained in training a fruit tree is, to make the plant produce as much fruit as possible; and for this purpose the branches are bent backwards and forwards to cause obstructions in the sap, as it is only from places where there is an accumulation of sap that flowers and fruit are produced. Another object in training standard trees is to let the air into the centre of the tree, so that it may ripen the wood; and a secondary object in training trees against a wall is, that every part of the wall may be covered. I cannot quit the subject of gardening without saying a few words on _manures_. The object of manuring ground is, to supply the soil with certain properties which are necessary for the nutrition of the plants, and this is done partly by mixing with it some kind of animal or of vegetable manure, and partly by adding some earth, in which the soil of the garden may be deficient. The new manures which have lately been so fashionable are of both kinds: guano is the dung of sea birds, which has been accumulating for ages on islands off the western coasts of Africa and South America; and nitrate of soda and Humphrey's compound are mineral substances which are very efficacious in promoting vegetation. The best vegetable manure is formed from decayed leaves, and this is a manure which may always be used with perfect safety; whereas the others are very injurious if used in too huge a quantity.