472] R A P tance of 12 or 14 inches apart. Sometimes rape and turnips are sown together; but such prattice is not economical ; as the two crops mutually injure each other. Rape yields most abundantly af- ter beans, turnips, or cabbages; the soil being previously ploughed twice, north and south, for the better reception of the solar heat ; and, if transplanted, such plants will vegetate with uncommon luxu- riance, so as amply to repay the ad- ditional expence. For this purpose, Mr. Hazard ('Letters a??d Papers of the Bath and JVest of England Society, &c. vol. iv.) recommends one rood to be sown in the middle of June, and to remove the young plants towards the middle of Au- gust^ ir.to ridges twofeet apart, and iit the distance of sixteen inches from each other. As soon as the)' have taken' root, and begin to shoot up, it will be necessary to manage them by the horse or hand-hoe; and to draw the earth around their stems. A. rood of land, thus scnvn, will, according to his experience, produce a sufficient number cf plants for the stocking of /t7/ acrts ; and in the following spring the leaves may be fed off with sheep ; because new ones will immediately succeed. But, as these tender plants are much infested by slogs, which devour them with avi- dity, it w.'il be advisable to scatter over them a mixture of slaked lin)e and wood-ahhes, in the proportion of 10 bushels of the former, to 15 of the latter, per acre. Rape-seed attains to maturity from July to September ; and, as it is easily shed, the plants are ge-ne- rally cut with sicisles; laid on the ground to dry; and the seed is yubbed out on a large cloth spread in ^he middle of the field, whence RAP It is conveyed to the mill. The oil which these seeds yield by expres- sion, is employed for various use- ful purposes in domestic life, and particularly for burning in lamps ; but, as it is apt to become rancid, M. Thenakd has published the following practical method o^ puri- fying it. -He dire6ls 1 } or 2 parts ot concentrated sulpuiric acid to be added to 100 parts of oil, and the whole to be perfectly incorpo- rated by agitation : the fluid imme- diately becomes turbid, assuming, a dark-green cast ; and, in the course of three quarters of an hour, the colouring particles begin to collect in lumps. The agitation must now cease ; and double the weight- of oil of vitriol, diluted with pure water, should be added : -'—in order to mingle these dilfcrent ingredients, the stirring ought to be renewed for the space of half an hour ; after which the whole may be left to .settle for seven or eight days. At the end of that time, the oil will be found on the surface ; on being gently drawn off, and iiltred through cotton or wool, it will be almost entirely di- vested of colour, smell, and taste ; so that it will barn clear, without any interruption, Tiie refuse of rape, after express- ing the oil, is known by the name of rape-cake ; the econoniical uses of which we have already stated, vol. i. p. 413. — The whole plant is of great service in feeding cattle ; and, after the seed is threshed, the straw and chaff, on being burnt, , afford ashes equally valuable as the; best pot-ashes. Lastly, if rape-straiv be strong, it may be advantageously employed for inclosing fences in farm-yards ; and, with still greater protit, for littering straw-yards, cow- sheds, or
