244 AGRICULTURAL TEXT-BOOK. 



no rain, watering in the evening is requisite for a few days. If 

 in ridges plant the slips 8 or 10 inches apart. When the weed 1 * 

 begin to appear dig or plow between the rows, clean round the 

 plants with a hoe, and draw a little dirt round thorn. When 

 plowed the last time about the last of July hill them up. 

 If the vines have grown across the furrows, turn them carefully 

 back, and afterwards replace them. No earth should be allow 

 ed to fall upon the vines ; and if they root, they should be pulled 

 up, otherwise small and worthless potatoes will be produced at 

 each root, and the main ones will be inferior in size. They 

 should be dug as soon as the frosts kill the vines. 



537. There is great difficulty in the north, in preserving 

 these tubers from decay during winter. The best mode appears 

 to be placing them in moderately sized boxes, and keeping them, 

 iu a room sufficiently heated to prevent frost, at an equal tem 

 perature; allowing them, however, to &quot;sweat&quot; before packing 

 them away. (See Patent Office Report, 1846, pp. 450-457, 

 Trans, of N. Y. Agricultural Society, Vol. viii, p. 426.) 



538. MUSTARD. (Sinapit nigra, and alia.) This plant is 

 very rarely cultivated in the United States, except on a small 

 scale; mcst of the mustard consumed in this country being im 

 ported from England, where the manufacture is confined to a 

 very few localities. There are or were mustard manufactories in 

 Philadelphia and New York, but the seed was chiefly imported 

 from Holland and Germany. The Black mustard is preferred 

 for this purpose, but becomes a very troublesome weed when 

 cultivated. Of late years, the White mustard has been sown 

 in rich soils in England for sheep feed during summer, for which 

 purpose it is found to be profitable, but in the United State** 

 both the climate and the Turnip Flea are injurious to it. This* 

 species cannot become a weed, as it is killed by a very slight 

 frost. It is occasionally used medicinally; and in Europe oil 



