Page:Collier's New Encyclopedia v. 03.djvu/398

DEXTROSE 344 DIABETES by the action of an azotized substance called diastase. Dextrin is used as a substitute for gxim. DEXTROSE, grape sugar, dextro- glucose, CeHisOe or CeHTOfOHK. Dex- trose occurs along with levulose in grapes and other sweet fruits, also in honey and in the urine of diabetic patients. It can be produced by the action of dilute sul- phuric acid on cane sugar, starch, cellu- lose, etc. It can be best obtained by boil- ing for several hours 50 parts of starch mth dilute sulphuric acid (100 parts of water to five parts of H2SO4). The solu- tion is then neutralized with chalk, fil- tered, boiled with animal charcoal to re- move traces of color, and then evaporated carefully to dryness, forming an amor- phous mass which contains about 60 per cent, of dextrose, the remainder bemg chiefly dextrin. Pure dextrose can be ob- tained by crystallization from alcohol. It turns polarized light to the right, and dissolves lime, baryta, oxide 01 lead, etc. Dextrose reduces an alkaline solution of cupric sulphate, giving a red precipi- tate of CU2O on heating. It reduces fer- ric salts to ferrous salts. Dextrose tastes much less sweet than ordinary cane sugar. By the action of sodium amalgam on dextrose it is converted into mannite, CeHwOe. DEY, a title formerly assumed by the rulers (under the Turkish Sultan) of Al- giers, Tripoli, and Tunis. The name was also formerly given to elderly people, es- pecially among the Janizaries; hence came to be commonly applied at Algiers to the commanding officers of that corps, who frequently became afterward a pasha or regent of that province. DHALAK (dha-lak'), an archipelago of the Red Sea, off the coast of Abyssinia. It contains nearly 100 rocks and islets, mostly uninhabited, clustering round the island of Dhalak el-Kebir, which is about 35 miles long by 30 broad. This island possesses a pearl fishery. DHAR, a tovm of central India, lying at an elevation of 1,908 feet above the sea, 33 miles W. of Mhov. It has over 20,000 inhabitants, and preserves, in two large mosques of red stone and a fort defended by a high rampart and 26 towers, traces of bygone magnificence. It is the capital of a protected state of the same name, with an area of 1,775 square miles, and a population of about 145,000. DHAR WAR, a town and district in the southern Mahratta country, in Bom- bay presidency, separated by the river Tungabhadra from Madras. The town has no manufactures of importance, but a good deal of trade. Pop. 30,000. The district has an area of 4,600 square miles, and a population of 1,100,000, mostly Hindus. The most interesting feature of the country is its suitableness for the growth of American cotton, which now occupies a third of the total acreage devoted to cotton. Cotton and silk cloth are manufactured in the district. The prevalent language is Canarese. DHOLPORE, a native state of Rajpu- tana, in central India, on the N. bank of the Chumbul, with an area of 1,200 square miles, and a population of 280,- 000, mostly Hindus. Capital, Dholpore, on the Chumbul, 34 miles S. of Agra. A large 15 days' fair is held every year at Machkund, a lake 3 miles to the W., with no fewer than 114 temples on its banks. DHOW (dou), an Arab sea-going ves- sel, ranging from a comparatively small size up to 250 tons burden, with one mast and a large, square sail. It is used for merchandise and is often employed in carrying slaves from the E. coast of Africa to Arabia. DHURRA, or DOURAH, Indian mil- let, the seed of Sorghum vulffare, after wheat the chief cereal crop of the Medi- terranean region, and largely used in those countries by the laboring classes for food. Varieties are g^rown in many parts of Africa, one of them known as Kaffir corn. DHWALAGIRI (dwa-la-ge're), once supposed to be the highest peak of the Himalayas, but now ascertained to be at most only the third in point of altitude, has a height of 26,826 feet above the sea. It is in Nepal, in lat. 29° N., and Ion. , 82° 30' E. DIABASE, a fine-grained, compact, crystalline-granular rock, tough and heavy. DIABASE APHANITE, a very fine- grained or compact variety of quartz- diabase, in which the constituents are not to be recognized without the aid of the lens or the microscope, DIABETES, a constitutional disease produced by malassimilation in the stomach, liver, kidneys, or in the blood, specially marked by a very excessive dis- cnartj ^ of urine, which is always sacchar- ine, excessive thirst, and great bodily emaciation. Dr. Thomas Willis, in the time of Charles II., first observed the con- stant presence of sugar in the urine. The quantity of urine passed may vary from 10 to 30 or more pints in the day, with intense thirst, the patient often drinking many quarts, or even gallons, daily. The density of the urine is usually increased, and from 400 to 900 grains of sugar