Spec. Plant. Willd. i. 443. Cl. 3. Ord. 2. Triandria Digynia. Nat. ord. Graminaceae. G, 142. Calyx two-valved, many-flowered; with a twisted awn on the back. Species 13. A. sativa.1 Common Oat. Off. AVENAe semina, Lond. Edin. Farina ex seminibus, Dub.

The seeds of the Oat decorticated, called Grits; and the seeds ground into meal.

Syn. Gruau d'avoine (F.) Habergrutze(G), Gewoone haver (Dutch), Havre (Dan.), Hafra (Swed.), Avena (I.), Avena (S.), Avea (Portug.).

The oat was found by Anson growing wild upon the island of Juan Fernandez, on the coast of Chili; but the place whence it was first brought to Europe has never been satisfactorily ascertained. The root is annual and fibrous, pushing up a culm or straw, which rises above two feet in height. The inflorescence is a loose panicle, with the subdivisions on long pendulous peduncles. The glumes of the calyx are two, marked with lines, pointed, unequal, and larger than the flower. There are usually two flowers and seeds in each calyx: they are alternate, conical: the smaller one is awnless; the larger puts forth a strong,two-coloured, bent awn from the middle of the back of the glumule; both seeds are fertile.

There are many varieties of this species of grain cultivated in the north of Europe.2 In this country, that which is called the potato-oat is considered the best; its grain is short and plump, with a thin, clean, bright, pale straw-coloured cuticle.

Oats, when freed from their cuticle only, are named grits; in which state, and ground into meal, they are dietetically and medicinally used. In both states they yield their fecula to water by coction; and form a nutritious amylaceous gruel. The nutrient qualities of oats are well known. In many places the meal forms the chief support of the poor; and for infants who are unfortunately deprived of their natural and proper nourishment, the breast milk, no better substitute can be adopted than thin grit gruel, mixed with good cow's milk. The gruel should not be kept longer than forty-eight hours, as it becomes acescent after that period.1

Dioscoridis.

In Scotland, some parts of England, a part of Siberia, and in the northern parts of Norway and Sweden, oats form the chief part of the vegetable nutriment of the inhabitants.

Qualities. - Oats are inodorous; and taste very slightly, but not unpleasantly, bitter. They have not been chymically examined; but the greater part of their substance appears to consist of fecula or starch.

Medical properties and uses. - Gruels, or decoctions of grits or of oatmeal, are excellent demulcents, and therefore very frequently prescribed in inflammatory diseases, diarrhoea, cholera, dysentery, calculus, and febrile affections. They may be sweetened, acidified, or used plain. They are also used locally in glysters; and the meal boiled with water into a thick paste forms an excellent suppurative poultice. Officinal preparation.-Pulvis pro Cataplasmate, D.