to gelatine; also containing nitrogen. The saccharine substances cannot form part of any animal tissue, but, when converted in the body into those of the oleaginous group, may like these last go to nourish the adipose and nervous tissues; but by far their greater portion is used in the maintenance of the animal heat. Starch seems to be converted into sugar, and sugar into lactic acid, in which form it is oxidized and burned off; oleaginous matters appear to undergo oxidation without any preliminary change; these non-nitrogenized compounds cannot minister to the plastic growth of the body, as is proved by the death from inanition of animals fed exclusively upon them. The articles of the albuminous group serve not only for nutrition, but for the maintenance of heat, if required, by their decomposition; the proportion of their 4 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 nutrition goes, the fibrine of animals, the albumen of eggs, the caseine of milk, and the gluten of wheat are equally acceptable to the organism. No one of these, however, is alone sufficient to support life; it is very remarkable, as Dr. Prout has observed, that the only single article of food naturally provided for the continued growth of animals, milk, contains albuminous 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, sublingual, and submaxillary glands, and the follicles of the mucous membrane of the mouth. Saliva is but little heavier than water, contains minute corpuscles and epithelial scales, and in health has an alkaline reaction greatest during and after meals. It consists of about 995 parts of water in 1,000, and 5 parts of solid matters; of the latter the most remarkable is ptyalin, to which the peculiar properties of the fluid are due; it closely resembles, but is not identical with, albumen and caseine; it acts the part of a ferment, and, according to Mialhe, 1 part is sufficient to convert 2,000 parts of starch into sugar; it also contains a compound of sulpho-cyanogen, not known to occur in any other animal product, and interesting in a medico-legal point of view; its salts are nearly those of the blood, and its alkaline reaction seems to be due to the basic phosphate of soda; the "tartar" of the teeth and salivary concretions consist principally of earthy phosphates and animal matter. The limpid secretion of the parotid and sublingual glands saturates the food during proper mastication, while the viscid submaxillary fluid facilitates swallowing when the tongue carries the mass back toward the pharynx. The amount of saliva secreted daily by man will average, according to Bidder and Schmidt, 34 lbs., though it varies with the character and frequency of the meals. Beside its mechanical action, it is believed that the saliva, by its peculiar ferment, acts chemically upon the farinaceous elements of

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the food, leading to the conversion of the starch into sugar, the action continuing even in presence of the acid of the stomach; there is no satisfactory evidence that saliva exerts any other than a physical action upon nitrogenized substances. When the food reaches the stomach the digestion is continued by the gastric juice, secreted by the numerous follicles of the mucous membrane, lined with lobular cells and glandular epithelium. Bernard's experiments show that the secretion is mainly poured out toward the pyloric extremity of the organ. The nature of the digestive process has been the subject of much speculation in past times. It was at first supposed that the aliments underwent a coction similar to that which they would experience in a vessel with hot water; to this succeeded the theory of acid fermentation, then of putrefaction, of trituration, and of maceration, till the present belief in the solvent action of the gastric juice was established. The gastric juice is transparent, nearly colorless, and with very slight viscidity. Its most characteristic feature is acidity, which is even perceptible to the taste. Many eminent chemists maintain that the real agent in the solvent process is free lactic acid, while others are in favor of free hydrochloric acid; the latter seems to be true of man, and the former of dogs and pigs, which have been the most frequent subjects of experiment. The peculiar organic ferment of the gastric juice is pepsin, which disposes albuminous matters to undergo solution by the contained hydrochloric acid, which they would otherwise only partially do unless exposed to a high temperature. The secretion of the empty stomach is neutral or alkaline, but it becomes acid on the introduction and during the digestion of food, resuming its neutral character when this process is finished. From the experiments of Dr. Dalton, it appears that an ounce of gastric juice will dissolve a little over 30 grains of fresh lean meat; at this rate the full digestion of a pound of raw meat would require 2 gallons of gastric juice; and this apparently enormous quantity will not be considered incredible, if it be recollected that this fluid after it has done its work of solution is at once reabsorbed into the circulation, so that even this quantity might be secreted during the 3 or 4 hours of the digestive process, at an expense to the blood of not more than 2 or 3 oz. of fluid at any one time; the fluid does not accumulate in the stomach, but its watery portions are in continual process of secretion and reabsorption as long as any food remains undigested, within reasonable limits as to quantity ingested. Many of the most important phenomena of gastric digestion have been rendered familiar and visible by the experiments of Dr. Beaumont and others within a few years on Alexis St. Martin, through an opening in whose stomach the effect of food, stimulants, and sedatives could be seen. The color of the membrane was pale pink, its appearance velvet-like, and its surface lined with a transparent viscid mucus; the irritation of food caused the innumer

able follicles to become prominent, and to pour out the acid gastric juice; small quantities of very cold water, or ice, after the primary sedative effect, caused turgidity of the membrane and copious secretion, while ice in large amount and long continued retarded the process. The amount of gastric juice secreted depends on the requirements of the system, and not on the quantity of food taken into the stomach; this is most important to be remembered, since, after the fluid secreted has dissolved all it can, any excess of food must remain undigested, pass into the intestines in a crude state, and become a source of pain and irritation until it is expelled. When the system is diseased, there is no craving for food, which if taken would not cause the secretion of the gastric juice, but would remain undigested for 24 or 48 hours, adding its irritation to the general diseased state. Excess in eating or drinking causes erythematic inflammation of the stomach, and acridity of the secreted fluid, which if long continued disorders digestion, and betrays itself to the physician by aphthous ulcerations and other morbid appearances of the mouth and tongue. The secretion of gastric juice is influenced by, though not dependent on, nervous agency; it is well known that mental emotion will put a stop to the digestive process, and section of the pneumogastric nerves arrests for a time the elaboration of the gastric fluid. There can be no doubt that the process of gastric digestion is essentially one of chemical solution, the solvent fluid being prepared by the follicles of the stomach, and its action assisted by the peristaltic muscular movements of the organ; the experiments on St. Martin fully prove these facts, both in natural and artificial digestion. Rapidity of digestion depends so much on the quantity and quality of the food, the state of health, the condition of the mind, and the habits of exercise, that it is difficult to determine the relative digestibility of different articles of diet; it appears from Dr. Beaumont'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 beef, mutton, 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, so generally used at the present day, must be very prejudicial to digestion. The most recent experiments go to show that the action of the gastric juice is confined to nitrogenized substances, and that it exerts no influence on starchy, saccharine, or oily matters. Starch is acted upon by the salivary fluid, sugar is dissolved, and oily substances are reduced to a state of

fine division without the agency of the gastric juice. Its action on albuminous matters is to reduce them to a complete solution, alter their chemical properties, and convert them into albuminose (a kind of imperfect albumen), in which form they are readily assimilated. In this condition they form definite combinations with the solvent liquid, which have been called peptones; these are not mere solutions of the respective substances in acidulated fluids, for a converting 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; the action of the biliary and pancreatic fluids has been noticed under BILE and CHYLE, and the end of the digestive act under CECUM. As mental depression will retard digestion, so a mind at ease and a joyful spirit will promote it. The merry laugh not only indicates a mental condition favorable for the natural secretion of the gastric juice, but by shaking the sides favors the movements of the stomach so essential to perfect digestion; so that the saying, "Laugh and grow fat," is founded upon physiological principles. Until digestion has been partially completed, both orifices of the stomach are closed, a beautiful provision of nature keeping the pylorus shut, and allowing no undigested matter to pass out, unless its faithful fibres are overpowered by too much or improper food. Indeed, the digestive system affords some of the most admirable proofs of creative design, whether we consider the mechanism of chewing and swallowing, the reduction of different alimentary articles to a homogeneous chyme, the absorption of some parts by the stomach itself and of others by the special lacteals, the changes effected by the secretions of the liver and pancreas, or the removal of superfluous and injuri ous substances. When it is remembered what control, for good or for evil, the human race has over these processes, it must be admitted that a knowledge of the physiology of digestion is of the first importance to health and happiness.-For further details on the subject of digestion, the reader is referred to Todd and Bowman's "Physiological Anatomy," Carpenter's works on physiology, and the work of Dr. Beaumont on "Digestion," edited by Dr. Andrew Combe; and for fuller information on articles of food to the titles ALIMENT and DIETETICS.

DIGGES, LEONARD, an English mathematician, born in the parish of Barham, Kent, died about 1574. He was educated at Oxford, was possessed of an ample fortune, and devoted himself to mathematical studies. He wrote "Teetonicum, 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).— THOMAS, only son of the preceding, died in 1595. He was graduated at Oxford, adopted the profession of a soldier, and was appointed muster-mas

DIGIT

ter general of the forces sent out by Elizabeth to assist the Netherlands. He wrote several mathematical treatises and other works, among which may be mentioned Ala, seu Scale Mathematica (1573); "A Letter on Parallax" (1573); "A Geometrical Treatise named Stratioticos, requisite for the Perfection of Soldiers" (1590); "A Perfect Description of the Celestial Orbs according to the most ancient Doctrine of the Pythagoreans" (1592), and some others.

DIGIT (Lat. digitus, finger), in arithmetic, one of the 10 figures or symbols by means of which all numbers are expressed. In astronomy, it designates a 12th part of the diameter of the sun or moon. Thus, an eclipse is said to be of 9 digits when three-fourths of the diameter of its disk are concealed.

DIGITALIS, a genus of exogenous plants be longing to the natural order scrophulariacea. Digitalis purpurea (Linn.), purple foxglove, is a small shrub found in pastures and about hedges on banks of streams, in a gravelly or sandy soil. Calyx 5-parted, unequal; corolla campanulate, the limbs obliquely 4-lobed; stamens 4; stigma simple; capsule ovate-acuminate; root of numerous long slender fibres, biennial; stem erect, 3 or 4 feet high, commonly simple roundish with slight angles, downy; leaves alternate, ovate-lanceolate or ellipticoblong, crenate, downy, rugged, and veiny, of a dull green color, tapering at the base into winged footstalks, lower ones largest; raceme terminal, long, simple, of numerous large, pendulons, odorless flowers. Fuchsius is regarded as the earliest botanist who mentions this plant, which he named digitalis (Germ. Fingerhut, finger stall), on account of the blossoms resembling the finger of a glove. The term foxe-glove occurs in a MS. Glossarium Ælfrica, written before the Norman conquest, and in a MS. Saxon translation of Apuleius, both of which are among the Cotton MSS. in the British museum; but no Latin or Greek name was given to this plant previous to Fuchsius in 1542. This beautiful shrub derives its chief interest from its medicinal properties, which reside in the leaves and seeds, the latter being small, roundish, and of a grayishbrown color. The effect of foxglove has been tried on dogs, horses, rabbits, turkeys, the domestic fowl, and frogs, and on all it has been found to act as a poison. According to Orfila, the first symptom of poisoning in carnivorous animals is vomiting. The cerebro-spinal symptoms observed in animals are diminished muscular power, convulsive movements, tremors, and insensibility. When given in small doses to man, it is found to exercise a remarkable influence over the circulation, frequently reducing the pulse from 70 or 80 to 40 or 50 beats in the minute. Dr. Baildon found that his own pulse was reduced by the use of digitalis from 110 to 40 beats per minute while he occupied a recumbent position, but upon rising it increased to 70 beats. This action, however, is far from being uniform. Dr. Sanders indeed asserts that its use is invariably attended by an increased

action of the pulse. The effects of digitalis more closely resemble those of tobacco than any other agent. It possesses in common with green tea the property of preventing sleep. In medicine it is usually employed: 1, to reduce the heart's action; 2, to promote the action of the absorbents; 3, as a diuretic; and 4, on account of its influence over the cerebro-spinal system. Large quantities of digitalis are exported from Germany to Cuba, where it is mixed with tobacco in the manufacture of cigars.

DIGITIGRADES, the tribe of the typical carnivora, so called because they walk on the ends of the toes, as distinguished from the plantigrades, which, like the bear, place the whole foot upon the ground. This tribe includes the mustelida or weasels, the canida or dogs, and the felide or cats. All have the cheek teeth with cutting edges, the lower shutting within the upper, dividing the flesh of their prey like the blades of scissors. As their food would indicate, they have a simple stomach and a short intestine. Their carnivorous propensity may be measured by the tubercle or heel on the lower carnivorous tooth, and the number of false molars in front and of tuberculous teeth behind it; those having the simplest carnivorous teeth, and the fewest molars in front and behind, like the cats and the weasels, are the most sanguinary. The characteristic marks in the skeleton are the long metacarpus and metatarsus, the elevation of the os calcis, and the shortness of the phalanges which alone rest upon the ground; and in the cats, the retractile claws. The extremities are formed for leaping and springing; from the pelvis as the fixed point, the 3 portions of the limbs are movable in alternately opposite directions; by the simultaneous flexion of these joints, and their sudden extension by means of powerful muscles, the greatest force is given to the spring, the elevated and elongated heel affording the principal mechanical advantage in the digitigrade foot.

DII, the Latin generic name for all the gods. The instinctive tendency of man, prompted also by every thing in the external world, is to believe in a divine agency and government. Amid the grand movements of the universe, and with consciousness of noble passions and faculties, he demands the origin, the law, and the destiny of himself and the objects by which he is surrounded; he asks what absolute masters govern the phenomena of nature, impel the streams, unchain the tempests, illumine and move the skies, guide the procession of the seasons, and start the germs of life. Asia, the birthplace of man, and the theatre of the earliest human societies, gave the first answers to these inquiries, sometimes deifying the elements, the heavenly bodies, and eminent men; sometimes marking the constant antagonisms of nature-how the shore confronts the sea, the wind and ocean wrestle together, and conscience and passion strive for the mastery of the human will-and therefore deifying two opposite principles of good and evil,

either of which would be supreme but for the other; and sometimes attaining the conception of one supreme deity whose spirit pervades all things. The Greek and Roman mythology, though it received some elements from the creations of the East, was mainly the work of the poets and legislators of Greece. Created and professed by the most artistic people of the past, it was submitted to by the triumphant Romans; during many centuries morality found support in it, and misfortune a refuge; philosophy adopted it, and poetry rendered it immortal. The principal divisions of nature were personified into great divinities, and forms, attributes, and a name were given to the smallest objects in the universe. Fable too and tradition become transfigured into mythology, and many of the gods and demigods were but the kings, heroes, and sages who preceded the historical times. Of divinities of various ranks, Hesiod says there were no fewer than 30,000 who inhabited the earth, and to this immense number many more were afterward added. The Romans generally made 3 classes of the gods. The first of these, the dii majores, were 12 in number, 6 males and 6 females, and their names are thus combined by Ennius in 2 hexameters:

Juno, Vesta, Minerva, Ceres, Diana, Venus, Mars, Mercurius, Jovi, Neptunus, Vulcanus, Apollo. These deities corresponded with the 12 Olympian gods of the Greeks, and constituted the divine council which presided over the course of human affairs. The Greeks added to these 12, Alexander the Great as the god of conquests, but he was not recognized as such by the Romans. The second class were the 8 dii selecti, Janus, Saturn, Genius, Sol, Bacchus, Tellus, Pluto, Luna, who were sometimes classed with the superior gods. The third class were the dii minores, comprehending a crowd of beings to whom limited divine honors were paid, and who were regarded as possessing a species of divine nature. Among these were the indigenous gods, attached to certain places of which they were the guardians, as the penates and lares, the protectors of home and family. The woods, rivers, fields, mountains, forests, and solitudes were all peopled with fauns, sylvans, satyrs, nymphs, dryads, and hamadryads. The agitation of the air came from the flight of the Zephyrs; the rainbow was the scarf of Iris; sound reverberating through the rocks was the nymph Echo; and all nature under the charm of this mythology became endowed with life and intelligence. There were the implacable Parcæ in collision with the sharply-cut Greek personality; and the avenging Furies, side by side with the

more heroic than moral Greek instincts. Some theologians have considered mythology founded upon religious ideas once revealed to man, but, in consequence of length of time and the action of an exuberant imagination, at length overgrown with fable. It was never so native to the Romans as to the Greeks, and before the era of Augustus the faith in it had ceased to be either a strong religious or aesthetic feeling. It

was degraded by the apotheosis of impious and monstrous Roman emperors, and passed away as Christianity gradually advanced.

DIJON (anc. Dibio or Divio), a town of France, former capital of the duchy of Burgundy, now the chief town in the department of Côte d'Or, seat of a bishopric, of a royal court, of tribunals of the first resort, and of a university with faculties of law, the sciences, and belles-lettres; pop. in 1856, 29,766. It is of an oval form, with several suburbs, and lies at the foot of a chain of mountains in a fertile vale, at the confluence of the rivers Ouche and Suzon, on the railway from Paris to Lyons, 160 miles S. E. of Paris. It is generally well built, and has numerous handsome public places and elegant houses. It is enclosed by ramparts, and its environs furnish delightful promenades. Dijon contains many remarkable buildings, the principal of which are the cathedral, formerly the Cistercian abbey of St. Benigne, a massive Gothic edifice founded in 535 and rebuilt in 1271, which contains the magnificent mansoleums of Philip the Bold and of John the Fearless; the church of Notre Dame, built in the 13th and 14th centuries; the church of St. Michael, which dates from the 15th century, remarkable for its front and its castle-like solidity; an ancient castle, the work of Louis XI., which served for a time in the 18th century as the prison of the duchesse de Maine, Mirabeau, and the chevalier d'Eon; the state palace, which contains archives and monuments of the middle ages of great value and a palace of the princes of Condé, built by Louis XI. and XII. It has also a school of the fine arts, 8 colleges, and 2 libraries, one of which contains 40,000 volumes. Its industry is active and varied, employed in the manufacture of linens, hosiery, vinegar, and candles, in distilleries and bleacheries, and in commerce in grain and wines. The origin of Dijon is traced back to times preceding the Roman dominion. Under Marcus Aurelius it was surrounded by walls flanked with towers, and was embellished and enlarged by Aurelian. It was burned by the Saracens in the 8th century, and sacked by the Normans in the 9th. It was again ravaged by fire in 1127, and was for 3 centuries the residence of the dukes of Burgundy and the seat of their brilliant court. By them its present fortifications were constructed. In 1513 it was besieged by the Swiss, and saved itself only by a humiliating treaty. It is the birthplace of some of the most eminent men of France, of Bossuet, Crébillon the elder, Piron, Rameau, Longepierre, Lamonnoye, Cazotte, Guyton-Morveau, and the duke

of Bassano.

DIKE, in geology, a wall of trap or other ig neous rock, which traverses other rocks, and appears to have been produced by the flowing of melted matter into a deep rent or fissure. Dikes are distinguished from veins by the greater uniformity of their contents, by the parallelism of their sides, by their not ramifying into smaller veins, and by their usually larger di

DIKE

mensions. The name was given them from their frequently projecting above the surface like a wall, owing to the degradation of the softer rock around them, dike being in the north of England and in Scotland a provincial name for wall. They are met with from a few inches to more than a mile in thickness. In volcanic eruptions they are seen in process of formation, as deep rents open and are filled with liquid lava. In the English coal mines trap dikes are occasionally met with in underground operations. They there form a wall across the line of the coal beds, cutting them off, and causing them at times to be thrown out of place. In the United States they occur likewise in the gold mines of North Carolina and in other metalliferous districts. The term is also used to denote a ditch, and is probably derived from the word to dig; but as applied to a sea wall or embankment, it comes no doubt from the Dutch word dijk, of the same signification. Such earth works were in former times a common means of defence, and were built around castles and fortresses. In Holland are the most remarkable dikes in the world, constructed to prevent the overflow of the lands reclaimed from the sea. Their immense importance may be appreciated from the fact that a single inundation from the sea in the year 1277 caused the destruction of 44 villages; and in 1287, only 10 years afterward, 80,000 persons were destroyed by another, and its present extent and shape were given to the Zuyder Zee. In the 15th century about 100,000 persons were again destroyed through the imperfection of the dikes, when their construction was undertaken in the most thorough manner, and a law was enacted enforcing their being kept in order. At present this work is conducted on a systematic plan and at great cost. Embankments are made toward the sea with heavy timbers filled in with stone, and the surface is covered with bundles of flags and reeds fastened down by stakes. Piles also are driven into the sand, and protected by planking as well as by earth, turf, and stones. These artificial dikes are often 40 feet above ordinary high water, and wide enough at top for a common roadway. Frequently the slopes are covered with wicker work made of willow twigs, and the willow tree is extensively cultivated to furnish these supplies, which require frequent renewal, as also to bind together by its roots the loose sands. Walls of masonry are built in some of the most exposed situations, and rows of piles outside protect the dikes from the action of the waves. It is estimated that the annual expense of keeping up the dike of Helder and that of West Cappel, at the western extremity of the island of Walcheren, is about $30,000 each. The whole expenditure in Holland for maintaining its dikes and regulating the water levels is annually from $2,000,000 to $2,500,000. Engineers are constantly employed, and every provision is made of materials that may be required for immediate repairs. Watchmen are employed during the winter months to patrol the dikes

by day and night, and give alarm whenever the danger appears imminent and the tide threatens to overflow. The people then hasten to the point, and by mats of straw and rushes and large sheets of sail-cloth buried in the sand they raise a temporary bulwark, to be more securely built before the approach of the next tide.Dikes are often constructed as barriers for reservoirs of water, and for this purpose they are built on several well established plans. The loose materials excavated for the channel or basin are piled up in a firm bank and consolidated by rolling with heavy rollers. Sometimes they are rendered more secure by building within them along their central line a puddle bank of selected clayey earth, mixed with sufficient sand to give it tenacity, so as not to crack in drying. This should be carried down to a solid foundation, and may be advantageously bedded upon a layer of concrete. It is built up a little later than the bank on each side of it, and both are rolled on the addition of every layer of 6 inches with a heavily ribbed roller of cast iron. The use of any material of the nature of quicksand is to be carefully avoided in any part of the embankment. Next the water it is well to face the work with a layer of broken stone that will pass through a 2 inch ring, and over this should be laid a sloping wall of flat stone at an inclination of 1 base to 1 vertical, or from that to one of 3 base to 1 vertical. The broken stone within is a guard against the embankment being penetrated by any small water animals. The dike around the great reservoir of 106 acres in the central park, New York, is made on the plan given above, which is approved by the engineers of France and England. It is 16 feet 8 inches wide at top, with an inner and outer slope of 13 base to 1 vertical. The puddle bank of clay in the centre, which reaches to within a few feet of the top, is 16 feet thick. The depth of water around the margin is 34 feet. At the surface of the water the thickness of the embankment is 24 feet 9 inches, and at 30 feet below it is 114 feet 9 inches. The French engineers give the preference to this mode of construction to that of a wall of masonry alone or of an embankment within a wall. Stone work by settling is liable to injury that can be repaired only at great cost, especially if the structure be concealed within an embankment. Where room is an object, as in the streets of a city, the outer sides of the dike are conveniently held up by steep walls of stone, the object of which is neither to add to the strength nor to the impermeability of the work.

DILETTANTE (pl. dilettanti), an Italian term, naturalized in France, England, and Germany, signifying an amateur, and applied to a person who especially interests himself in any art, without knowing its fundamental principles, and without making it an object of thorough study. The term dilettante designated originally a lover of Italian vocal music, and was at one time the name of a party which maintained the