COMSTOCK, Theodore Bryant (1849-1901). An American geologist, born at Cuyahoga Falls, Ohio. He graduated at the Pennsylvania State College in 1868, and at Cornell in 1870, and in 1873 accompanied Capt. W. A. Jones's Wyoming and Yellowstone Park expedition as geologist. From 1875 to 1879 he was professor of geology and paleontology at Cornell, where he established the department of economic geology. He acted in 1879-84 as general manager of a mining company at Silverton, Cal., and from 1884 to 1889 occupied the chair of mining engineering and physics at the University of Illinois. He was assistant State Geologist of Texas in 1889-91; in the latter year founded the Arizona School of Mines, which he directed until 1895, and from 1893 to 1895 was president of the University of Arizona. In 1886 he was elected secretary of the geological and geographical section of the American Association for the Advancement of Science. He published an Outline of General Geology (1878); Classification of Rocks (1877); and other works.
COMSTOCK LODE. A remarkable compound fissure vein, rich in gold and silver, located in Storey County, Nev., on the eastern slope of Mount Davidson, a northeastern spur of the Sierras, at a point about 20 miles east of the California State line. Its discovery in 1859, when it received the name Washoe, created great excitement and led to the building up of Virginia City. The vein is about four miles in length, and varies in width from zero at the ends to 3000 feet at the middle point. It occupies a zone of displacement in igneous rocks, chiefly andesites of Tertiary age. The ore, which is of high grade, containing both silver and gold in proportion of three of the former to two of the latter, occurs in great pockets known as bonanzas, chiefly along the eastern portion of the vein. The excavations along this fissure vein have been carried to great depths, approximating 3500 feet, until operations became difficult through the inflow of hot water with a temperature of 170° F. The Sutro Tunnel, with a length of four miles, was driven with a view to draining this water, but with only partial success. The richness of the ore of this lode may be realized from the value of the product, the total value during the years 1860-90 having been $340,000,000; the greatest output for a single year was $38,000,000 in 1877. Since 1890 the production has declined.
Besides its economic value, the Comstock Lode is of great interest in other directions. One of the earliest classifications of igneous rocks (q.v.) was attempted in connection with the study of the geologic relations of the ore bodies by Von Richthofen in 1868; and Van Hise, Iddings, and Becker have at a later period perfected the modern classification of igneous rocks with aid of considerable information derived from the Comstock Lode and Sutro Tunnel. Also many important observations have been made on the relation between the size of grain and the rate of cooling, and upon the rate of development of crystallization in igneous rocks. Again, experiments have here been carried on by Carl Barus with the object of determining the temperature variations and electric manifestations in the deeper workings. For more precise information on the geologic features and methods of mining of the Comstock Lode, the reader is referred to the two following works: Becker, "Geology of the Comstock Lode and Washoe District," with folio atlas; being Monograph of the United States Geological Survey, vol. iii. (Washington, 1882); Lord, “Comstock Mining and Miners,” Monograph of the United States Geological Survey, vol. iv. (Washington, 1883).
COMTE, kôNt, Isidore Auguste Marie François Xavier (1798-1857). A celebrated French philosopher, the founder of the positive philosophy, or Positivism (q.v.). He was born at Montpellier, and educated at the Ecole Polytechnique in Paris, from which he was expelled for his part in a protest of students against one of the instructors. From 1816 he supported himself by tutorial work. In Paris he met Saint-Simon, with whose theories he was at first greatly charmed, but from whose influence he broke away in 1824. In the following year he married Caroline Massin, but the union was unhappy. In 1826 he began a course of lectures at his own house on his system of philosophy, and had among his hearers such men as Humboldt and Blainville. Excessive work, however, ruined his health, and after the third lecture he became insane, was taken to an asylum, and tried to commit suicide. Thanks to the care of his mother and wife, he soon recovered the use of his faculties, and took up his studies and lectures again. In 1835 he got a position as examiner for entrance to the Ecole Polytechnique, which he held for some ten years, after which he was largely supported by his pupils and admirers. John Stuart Mill, with whom Comte had been in correspondence for some time, induced some wealthy English friends, Grote among them, to advance about $1200 to Comte in 1845, and Grote sent a small sum to him afterwards. In 1848 Littré headed an appeal for a public subscription for the benefit of Comte, on the proceeds of which he subsisted for the remainder of his life. In 1845 he met Clotilde de Vaux, whose husband was serving a life sentence, and conceived an extravagant affection and admiration for her. The relation, which seems to have been platonic, was broken by her death a year later, after which Comte had a second attack of mental alienation. His death took place on September 5, 1857.
Comte published a number of important philosophic works, the most famous being his Cours de philosophie positive (6 vols., 1830-42), of which a condensed English translation by Harriet Martineau, approved by the author, appeared in 1853. Other works were: Traité élémentaire de geometrie analytique (1843); Traité d'astronomie populaire (1845); Système de politique positive (4 vols., 1851-54; English translation, London, 1875-77); Catechisme positiviste, on sommaire exposition de la réligion universelle (1852). Comte's central and governing doctrine is that the human race, like the individual, necessarily passes through three intellectual stages: (1) The theological, in which n supernatural origin is sought for all phenomena, and the deus ex machina is the only explanation of events. (2) The metaphysical, in which the sensuously supernatural is set aside as incredible, and an effort is made to demonstrate the existence of “abstract forces or entities supposed to inhere in various substances, and capable of engendering phenomena.” (3) The positive, in which the mind affirms the futility of both theological and metaphysical in-
