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106 DIGGES DIGITALIS the habits of exercise, that it is difficult to de- termine the relative digestibility of different articles of diet. It appears from Dr. Beau- mont's researches that, other things being equal, the flesh of wild animals is more easily digested than that of the allied domesticated races ; in this respect venison stands first, then turkey, then mutton, beef, and veal, in the order mentioned. A certain bulk of food is necessary for healthy digestion, as has long been practically known by uncivilized nations ; soups and fluid aliment are not more readily chymified than solid substances, and cannot alone support the system in vigor. Moderate exercise before a meal facilitates digestion. A temperature of 98 to 100 F. is requisite for the perfect action of the gastric juice; hence the ingestion of cold and iced substances, if carried to such an extent as to depress the temperature of the stomach, must be very prejudicial to digestion. The most recent ex- periments go to show that the action of the gastric juice is confined to nitrogenized sub- stances, and that it exerts no influence on starchy, saccharine, or oily matters. Its ac- tion on albuminous matters is to reduce them to a complete solution, alter their chemical properties, and convert them into albuminose (a kind of modified albumen), in which form they are readily assimilated. In this condition they form definite combinations with the sol- vent liquid, which have been called peptones. These are not mere solutions of the respective substances in acidulated fluids ; for a convert- ing power is exerted by the pepsin, the solvent power being due to the acid of the gastric juice. The process of digestion is far from being completed in the stomach, but goes on in the intestine by the continued action of the gastric juice, as well as by that of the pancrea- tic and intestinal juices. Of these, the intes- tinal juice seems to have the power of rapidly transforming starchy matters into a form of sugar, while the pancreatic juice, on coming in contact with the fatty elements of the food, converts them into a finely divided milky -look- ing emulsion, known as chyle. All these sub- stances, the fluid products of digestion, are then gradually taken up by the blood vessels and lac- teals of the alimentary canal, and mingled with the general mass of the circulating fluid ; until in the lower part of the intestine there are left only the indigestible and refuse parts of the food, mingled with the excrementitious sub- stances of the large intestine. (See ALIMENT, ALIMENTARY CANAL, and DIETETICS.) DIGGES. I. Leonard, an English mathemati- cian, born in the parish of Barham, Kent, died about 1574. He was educated at Oxford, pos- sessed an ample' fortune, and devoted himself to mathematical studies. He wrote " Tectoni- cum, briefly showing the exact Measuring and speedy Reckoning of all manner of Lands, Squares, Timber, Stones, Steeples, &c." (1556); Pantometria, a practical geometrical treatise (1591); and "Prognostication Everlasting of right good effect, or Choice Rules to judge the Weather by the Sun, Moon, and Stars " (1555). II. Thomas, son of the preceding, died in 1595^ He graduated at Oxford, adopted the profes- sion of a soldier, and was appointed muster- master general of the forces sent out by Eliza- beth to assist the Netherlands. He wrote sev- eral mathematical treatises and other works, among which are : Alee, sen Scales Mathema- ta'c!(1573); "A Letter on Parallax" (1573)- and " A Perfect Description of the Celestial Orbs according to the most ancient Doctrine of the Pythagoreans " (1592). DIGITALIS, a genus of exogenous plants be- longing to the natural order scroptiulariace. Digitalis purpurea (Linn.), purple foxglove, is a small herb found wild in Europe about hedges on banks of streams, in a gravelly or sandy soil. Calyx 5-parted, unequal ; corolla campanulate, the limbs obliquely 4-lobed ; sta- mens 4 ; stigma simple ; capsule ovate-acumi- Digitalis purpurea. nate; root of numerous long slender fibres, biennial ; stem erect, 3 or 4 ft. high, com- monly simple roundish with slight angles, downy; leaves dull green, alternate, ovate- lanceolate or elliptic-oblong, crenate, downy, rugged, and veiny, tapering at the base into winged footstalks, lower ones largest ; raceme terminal, long, simple, of numerous large, pen- dulous, odorless flowers. Fuchs is regarded as the earliest botanist who mentions this plant, which he named digitalis (Germ. Fingerliut, thimble), on account of the blossoms resem- bling the finger of a glove. The term foxe-glove occurs in a MS. Olossarium JElfrica;,, written before the Norman conquest, and in a MS. Saxon translation of Apuleius, both of which are among the Cotton MSS. in the British mu- seum ; but no Latin or Greek name was given to this plant previous to Fuchs in 1542. Thia beautiful plant derives its chief interest from its medicinal properties, which reside in the leaves and seeds, the latter being small, round-