104 DIGESTION with the king in the dissensions of the time, and was imprisoned by order of parliament. Da- rin" his confinement he wrote several treatises. He was released in 1643 at the intercession of the queen of France, and retired to that coun- trv, -herehe was received with great honor. From this time till 1661 he lived mostly on the continent, and especially in France, employing himself with literary and scientific labors. Having returned to England, he enjoyed the favor of Charles II., and continued his philo- sophical studies until his death. He married a daughter of Sir Edward Stanley, and his cu- rious experiments to preserve her extraordinary beauty gave him quite as much celebrity as his books. His principal works are : u A Confer- ence with a Lady about the choice of a Reli- gion" (Paris, 1638); "Observations on Reli- gio Medici" (London, 1643); a "Treatise on the Nature of Bodies " and " Treatise on the Soul, proving its Immortality" (Paris, 1644); a "Treatise of adhering to God" (London, 1654); "Of the Cure of Wounds by the Powder of Sympathy" (London, 1658); and "Private Memoirs of Sir Kenelm Digby, &c., written by Himself," first published in 1827. Hi Kenelm Henry, an English author, descended from an uncle of the preceding, born in 1800. His father, the Rev. William Digby, was dean of Clonfert, Ireland. He graduated at Trinity college, Cambridge, in 1823, embraced soon after the Roman Catholic faith, studied scho- lastic theology and the literature and antiquities of the middle -ages, and devoted himself exclu- sively to the illustration of mediaeval times and manners. In 1826-'7 he published "The Broad Stone of Honor : on the Origin, Spirit, and Institutions of Christian Chivalry." Pur- suing with unflagging industry his archaeolo- gical studies in the various countries of con- tinental Europe, the fruits of his research ap- peared anonymously from 1844 to 1847, under the title of "Mores Catholici, or Ages of Faith " (3 vols. royal 8vo, London). In 1851 appeared " Compitum, or the Meeting of the Ways at the Catholic Church;" in 1856, "Lover's Seat: Katheraerina" (2 vols. 12mo); in 1858, "Children's Bower, or What You Like " (2 vols. 12mo) ; in 1860, "Evenings on the Thames" (2 vols. 12mo; 2d ed., 1864); and in 1861, "The Chapel of St. John, or a Life of Faith," being a memorial to his de- ceased wife. DIGESTION (Lat. digerere, to dissolve or con- coct), the liquefaction and preparation of the food in the alimentary canal. The organs by which this function is performed in the higher animals are the mouth, pharynx, oesophagus, tomach, and intestines, with their accessory salivary glands, pancreas, liver, and mucous follicles. The first act to which food is sub- jected i> tin- mechanical division by the teeth. This process is important in order to reduce the food from a crude mass to a finely divided p:i-ty condition, in which it is more readily and thoroughly affected by the digestive se- cretions of the alimentary canal. While some of the nutritive matters are dissolved in and absorbed directly from the stomach, others re- quire further preparation, and are taken up by the vessels and absorbents of the intestines; by the time that the residue arrives in the cae- cum, almost all the alimentary matter has been extracted, and the insoluble portions with the excess of biliary and mucous secretions are voided at the anal termination of the canal. The digestive process can hardly be separated from absorption, which takes up the nutritive materials, and assimilation, which converts them into a fluid resembling blood, poured into the circulation near the heart. Though inorganic substances are necessary for the sup- port of the body, the organic alone are gene- rally considered as food and as subjects for the digestive process. Organic substances used as food may be conveniently arranged under three heads: 1, the saccharine group, em- bracing substances composed of oxygen, hy- drogen, and carbon, resembling sugar in com- position, and readily convertible into it ; such are starch, gum, woody fibre, and the cellulose of plants ; 2, the oleaginous group, with a great preponderance of hydrogen and carbon, small proportion of oxygen, and absence of nitrogen, including vegetable oils and anim * fats; 3, the albuminous group, containing large proportion of nitrogen, comprising mat and vegetable substances allied in ch cal composition to albumen and animal tissu The saccharine substances taken as food do not directly form part of any animal tissue, but are decomposed in their passage through the circulation, and are thus employed in some unknown way in the nourishment of the body. Starch is converted into sugar during diges- tion, and the sugar thus formed, as well as that taken under its own form with the food, is de- composed and appropriated as above. These substances, however, are not sufficient by them- selves for the support or growth of the body, as is proved by the death from inanition of animals fed exclusively upon them. The arti- cles of the albuminous group serve not only for nutrition, but for the maintenance of heat by their decomposition; the proportion of their four elements is the same in all, and they are all capable of reduction to a like condition by the digestive process, so that, as far as nu- trition goes, the fibrine of animals, the albu- men of eggs, the caseine of milk, and the gluten of wheat are equally acceptable to the organ- ism. No one of these, however, is alone suffi- cient to support life. It is very remarkable, as Dr. Prout has observed, that milk, the only single article of food naturally provided for the continued growth of animals, contains albumi- nous caseine in its curd, a good deal of oily matter, and considerable sugar. Supposing mastication to have been thoroughly performed, the food is first acted upon by the salivary fluid, which is secreted by the parotid, sufr lingual, and submaxillary glands, and the fol-
