Putty is a compound of boiled linseed oil and whiting, but as it may be bought in London at half-a-guinea per cwt., it is scarcely worth the gardener's while to make it. One hundred weight is enough for puttying about three hundred square feet of glass.

Old putty may be softened by applying to it rags dipped in a saturated solution of caustic potash, leaving them on for twelve hours; or by rubbing a hot iron along the putty.

If the gardener does make putty, the whiting should be well dried, and then pounded and sifted till it becomes a fine powder, and is quite free from grit. The whiting, a little warm, should be gradually added to the oil, and well mixed by means of a piece of stick, or a spatula. When it is sufficiently stiff, it should be well worked with the hand on a table, and afterwards beaten on a stone with a wooden mallet, till it becomes a soft, smooth, tenacious mass. A ball of putty, when left some days, becomes somewhat hard, but may be easily softened by beating.