The tubers are very varying in quality, because, the plant being perennial, they are sometimes left in the ground 340 THE SPIRIT OF COOKERY during two or three years, while the green parts above ground are cut and used for fodder. Such old tubers are good for cattle but indigestible by man. The tubers contain 79-59 per cent, of water ; nitrogenized substance, 1-98 per cent. ; fat, 0-13 per cent. ; sugar, 4-83 per cent. ; inulin, 1-1 per cent. ; other carbo-hydrates free from nitrogen, 9-13 per cent. ; woody fibre, 1-47 per cent. ; ash, 1-17 per cent. The 9-13 per cent, of carbo-hydrates consist mainly of a principle formerly termed synanthrose, but which it is proposed to term IcBVulin, from its turning a polarized ray of light to the left. Inulin, IcBvulin and sugar of the topin- ambur tubers are said to stand in the same relation to each other as starch, dextrin, and grai:)e-sugar. The ash of the tubers contains more silica and soda, and less potash, than the ash of the potato. The laevulin carbo-hydrates of the tubers are transformable into fermentable sugar, and the sugar present as such is also fermentable. Some chemists have obtained as much as 14'8 per cent, of sugar from tubers, and it was proposed to use them for the production of spirit ; but the yield is too varying, and the still will not be a com- petitor with the kitchen in the market for this tuber. The topinambur tubers when boiled assume a gray, semi- translucent aspect, which suggests the condition to be expressed by the adjective ‘watery.’ Owing to the solu- bility of the ingredients, boiling water must abstract much of their quality. It is therefore preferable, whenever feasible, to stew them and keep all the principles together. This also applies to the flavour, which is strongest in the stewed preparation. When boiled, serve the tubers with a white sauce ; when stewed, accommodate them with Italian sauce. ■ Batatas, or Yams. The name batata of this American tuber has given rise to the misnomer ‘ potato ’ which the Solanum tuberosum bears in England. It is also called in its home ignainc, whence the POTATOES 34i European yciin. In botany the plant passes as Dioscovea batatas, Ipomcea batatas, and Convolvulus batatas. The tuber has a sweetish taste, and is not so attractive as the potato ; it is also more pulpy or pasty, so that a baked batata has to be eaten with a spoon out of the peel as a bag. It contains 75'78 per cent, of water ; nitrogenized matters, 1’52 per cent. ; fat, 0'36 per cent. ; matter free from nitrogen, 20'06 per cent.; woody fibre, 1'07 per cent. ; ash, 1'21 per cent. The extractives free from nitrogen are, sugar, 1'73 per cent. ; gum and dextrin, 2'23 per cent. ; starch, 14*75 per cent., and other matter, 1*35 per cent. The starch made from them is sold in trade as ‘ Brazilian arrowroot, and serves mainly for the purpose of adulterating the true arrowroot. Yams may be stewed, fried either as they are, in slices, or dipped in batter {au beignets). Potatoes.

AI-modernized reading of the original text

The tubers are very varying in quality, because, the plant being perennial, they are sometimes left in the ground during two or three years, while the green parts above ground are cut and used for fodder. Such old tubers are good for cattle but indigestible by man. The tubers contain 79-59 per cent, of water ; nitrogenized substance, 1-98 per cent. ; fat, 0-13 per cent. ; sugar, 4-83 per cent. ; inulin, 1-1 per cent. ; other carbo-hydrates free from nitrogen, 9-13 per cent. ; woody fibre, 1-47 per cent. ; ash, 1-17 per cent. The 9-13 per cent, of carbo-hydrates consist mainly of a principle formerly termed synanthrose, but which it is proposed to term laevulin, from its turning a polarized ray of light to the left. Inulin, laevulin and sugar of the topinambur tubers are said to stand in the same relation to each other as starch, dextrin, and grape-sugar. The ash of the tubers contains more silica and soda, and less potash, than the ash of the potato. The laevulin carbo-hydrates of the tubers are transformable into fermentable sugar, and the sugar present as such is also fermentable. Some chemists have obtained as much as 14'8 per cent, of sugar from tubers, and it was proposed to use them for the production of spirit ; but the yield is too varying, and the still will not be a competitor with the kitchen in the market for this tuber. The topinambur tubers when boiled assume a gray, semitranslucent aspect, which suggests the condition to be expressed by the adjective ‘watery.’ Owing to the solubility of the ingredients, boiling water must abstract much of their quality. It is therefore preferable, whenever feasible, to stew them and keep all the principles together. This also applies to the flavour, which is strongest in the stewed preparation. When boiled, serve the tubers with a white sauce ; when stewed, accommodate them with Italian sauce. ■ Batatas, or Yams. The name batata of this American tuber has given rise to the misnomer ‘ potato ’ which the Solanum tuberosum bears in England. It is also called in its home igname, whence the POTATOES European yciin. In botany the plant passes as Dioscovea batatas, Ipomcea batatas, and Convolvulus batatas. The tuber has a sweetish taste, and is not so attractive as the potato ; it is also more pulpy or pasty, so that a baked batata has to be eaten with a spoon out of the peel as a bag. It contains 75'78 per cent, of water ; nitrogenized matters, 1’52 per cent. ; fat, 0'36 per cent. ; matter free from nitrogen, 20'06 per cent.; woody fibre, 1'07 per cent. ; ash, 1'21 per cent. The extractives free from nitrogen are, sugar, 1'73 per cent. ; gum and dextrin, 2'23 per cent. ; starch, 14*75 per cent., and other matter, 1*35 per cent. The starch made from them is sold in trade as ‘ Brazilian arrowroot, and serves mainly for the purpose of adulterating the true arrowroot. Yams may be stewed, fried either as they are, in slices, or dipped in batter {au beignets). Potatoes.

The spirit of cookery