Farina implies generally vegetable flour. The flour of the Parisian bakers (which it may be presumed is chiefly, if not wholly, wheaten,) was ascertained by M. Vauquelin to consist of gluten 10.2, starch 72.8, sweet matter 4.2, gummy glutinous matter 2.8, and moisture 10, in 100 parts. The farina of many vegetables consists almost entirely of starch, as is the case with rice, arrow root, and the potatoe. The method of separating the farina from the latter root is described with figures under the word Bread. A patent was granted in 1829, to Mr. Benjamin Goulson, of Pendleton, near Manchester, for " certain improvements in the manufacture of farina and sugar from vegetable productions." The specification explains it to consist in a method of converting dahlias, beets, carrots, mangel wurzel, and other roots, by the application of acid. After the roots have been well cleaned by washing, and cleared from their skins by rubbing or other process, they are to be sliced or grated, and steeped in a mixture of pure water and acid (the preference being given to sulphuric acid), in a ratio varying from two to ten pounds of acid (according to the roots operated upon,) to a hundred weight of roots. Those which possess the least natural sweetness will probably require the most acid.

In this mixture the roots are to be kept till they become quite soft or pulpy, when they are to be washed with pure water till they cease to taste of the acid. They are next to be dried in the sun or in an oven, and then be ground into flour, and used for making bread, or other purposes for which wheaten flour is employed. To extract the saccharine matter from roots, Mr. Goulson employs a second dose of diluted acid, in the proportion of from two to ten pounds of the acid to a hundred weight of the farina thus obtained, and by this means the fibrous parts become macerated; after which the acid is to be neutralized and separated from the saccharine portion, which is then to be clarified by the usual processes; or the saccharine matter may, by continuing the first process, and using an additional quantity of acid, be obtained at once without first converting the roots into flour.