passes. These insignia were in strictness ordered to be borne only in "targets hollow at the chief flankes," yet we often find them on shields, and sometimes even impaled and quartered with arms. Merchants, along with a monogram of their initials, often bore a mark composed of a cross and a figure resembling the figure 4 turned backward-perhaps a symbol of the Holy Trinity, though it has also been explained to represent the mast and yard of a ship. The insignia of their companies were frequently borne by merchants in a chief above their marks, and occasionally quartered with them. These merchants' marks were probably the origin of the trade-marks of the present time.

Mesmerism was first brought into notice by Frederick Anton Mesmer, a German physician, in 1766, when he published a thesis on "The Influence of the Planets on the Human Body," claiming that the heavenly bodies diffused through the universe a subtle fluid which acts on the nervous system of animated beings; and he further stated that he regarded the new force, which, he said, could be exerted by one living organism upon another, as a means of alleviating or curing disease. In 1778 he left Vienna for Paris, where he gained numerous proselytes and much money. His discovery was fostered by Dr. D'Elson, physician to the King's brother, and in 1784 the French Government ordered the medical faculty of Paris to investigate Mesmer's theory. A committee was appointed, who subsequently reported that "The violent effects which are observed in the public practice of magnetism are due to the manipulations, to the excitement of the imagination which leads us to repeat anything which produces an impression upon the senses.' One year later, 1785, Mesmer's popularity had so far declined that he left Paris and retired to Switzerland, where he spent the balance of his life. Mesmerism excited some attention again in 1848, when Miss Harriet Martineau and others announced their belief in it.

Meteoric Stones.-A meteoric stone, which is described by Pliny as being as large as a wagon, fell near Ægospotami, in Asia Minor, in 467 B. C. About A. D. 1500 a stone weighing 1,400 pounds fell in Mexico, and is now in the Smithsonian Institute at Washington. The largest meteoric masses on record were heard of first by Captain Ross, the Arctic explorer, through some Esquimaux. These lay on the west coast of Greenland, and were subsequently found by the Swedish Exploring Expedition of 1870. One of them, now in the Royal Museum of Stockholm, weighs over 50,000 pounds, and is the largest specimen known. Two remarkable meteorites have fallen in Iowa within the past thirteen years. On February 12, 1875, an exceedingly brilliant meteor, in the form of an elongated horseshoe, was seen throughout a region of at least 400 miles in length and 250 in breadth, lying in Missouri and lowa. It is described as "without a tail, but having a sort of flowing jacket of flame. Detonations were heard, so violent as to shake the earth and to jar the windows like the shock of

an earthquake," as it fell, at about 10:30 o'clock P. M., a few miles east of Marengo, Iowa. The ground for the space of some seven miles in length by two to four miles in breadth was strewn with fragments of this meteor, varying in weight from a few ounces to seventy-four pounds. On May 10, 1879, a large and extraordinarily luminous meteor exploded with terrific noise, followed at slight intervals with less violent detonations, and struck the earth in the edge of a ravine near Estherville, Emmet County, Iowa, penetrating to a depth of fourteen feet. Within two miles other fragments were found, one of which weighed 170 pounds and another thirty-two pounds. The principal mass weighed 431 pounds. All the discovered parts aggregated about 640 pounds. The one of 170 pounds is now in the cabinet of the State University of Minnesota. The composition of this aerolite is peculiar in many respects; but, as in nearly all aerolites, there is a considerable proportion of iron and nickel.

Mica consists of a silicate of aluminum combined, according to species, with small proportions of potash, soda, lithia, oxide of iron, oxide of manganese, etc. The most common and serviceable variety is known as potash mica. It is a constituent of granite, gneiss, mica slate, and several other kindred rocks. It is found both disseminated and in veins. It is very widely distributed, especially in composition with other minerals, but there are comparatively few localities where it is known to exist in such quantities and form as to be mined with profit. Its most valuable form is that of muscovite, in which it appears in translucent laminæ or plates. The larger and clearer these plates, the greater the value of the mine or quarry. In Siberia they have been found more than three feet across, and they have been obtained of great size in Sweden and Norway. This is also the case at Acworth, Grafton and Alstead, N. H. Mica is used largely for the doors of stoves and the sides of lanterns. It is employed in some countries as a substitute for window-glass, and its toughness recommends it for this purpose on board vessels of war. Lithia mica contains a small proportion of lithia, which gives it in many cases a fine rose or peachblow color, so that it is used for ornamental purposes. Potash mica, when ground in a fine powder, is used to give a brilliant appearance to walls, and as a sand for drying ink or paper.

Microphone, The, is the black carbon button used in telephones, and is an instrument for magnifying sound. The most sensitive substance, so far as yet discovered, to have the peculiar power, when placed in the electric current, of magnifying sound, is willow charcoal plunged, when at white heat, into mercury. A piece of such charcoal an inch long, placed vertically between two blocks of carbon, hollowed to receive its ends, wires connecting the blocks with an electric battery, and the ordinary receivinginstrument of a telephone, constitute one of the simplest forms of a microphone. The invention of the microphone is claimed by

Professor Hughes of England, and Thomas Edison, the American inventor.

Microscope, Invention of the.-It is generally believed that the first compound microscope was made in 1590 by a Hollander named Zacharias Jansen. Pocket microscopes were first made in London in 1740 by Benjamin Martin. The discovery of the magnifying power of the simple lens was undoubtedly made long before the Christian era, as it is known that the Greeks used magnifiers of glass which they called "reading-glasses," and rude lenses of crystal have been found in Egyptian ruins.

sun:

Midnight Sun, Land of the.-In his book on the travels and explorations which led up to the discovery of the remains of the famous and ill-fated Franklin expedition to the Polar regions by the expedition under Lieutenant Schwatka in 1878, Mr. Gilder, the second in command, writes as follows regarding the midnight "We were beginning to get used to the phenomena of the Arctic region, not the least among which is the midnight sun.' It is difficult for one who has not witnessed it himself to understand the meaning of this portent. The idea of the long Arctic night seems to be much more generally comprehended. Nearly all writers upon the subject, whether those who have themselves experienced its effects or those whose knowledge is derived from study, dwell with great force on the terribly depressing effect upon the physical organization of natives of the median zones caused by the long Arctic night whenever brought within its influence. Though much less has been written or said concerning the interminable day, its effects are almost as deleterious upon the stranger as the prolonged night. Indeed, to the sojourner in high latitudes the day is much more appreciable, for at no point yet visited by man is the darkness the total darkness of night throughout the entire day, while the midnight sun' makes the night like noon-day. Even when the sun passes below the horizon at its upper culmination the daylight is as intense as at noon in lower latitudes, when the sun's disk is obscured by their clouds. The long twilight in the north, where the sun's apparent path around the earth varies so little in latitude at its upper and lower culminations, takes some of the edge off of the prolonged night at the highest latitude ever attained by the Arctic explorer; but there is nothing to relieve the long weary day of its full power upon the system. There (in the north), in the spring, the sun never sets. There is no morning and no night. It is one continuous day for months. At first it seems very difficult to understand this strange thing in nature. The world seems to be entirely wrong, and man grows nervous and restless. Sleep is driven from his weary eyelids, his appetite fails, and all the disagreeable results of protracted vigils are apparent. But gradually

he becomes used to this state of affairs, devises means to darken his tent, and once more enjoys his hour of rest. In fact, he learns how to take advantage of the new arrangement, and when

traveling pursues his journey at night, or when the sun is lowest, because then he finds the frost that hardens the snow a great assistance in sledging.'

Military Divisions and Departments.-The United States are divided into three military divisions and six military departments. The Division of the Atlantic, also the Department of the East, includes the New England States and all States east of the Mississippi River except Illinois, Arkansas and Louisiana. The Division of the Missouri comprises the Department of the Platte, States of Iowa and Nebraska, and Territories of Utah, eastern Idaho and southern Wyoming; the Department of Dakota, States of Minnesota, North and South Dakota and Montana, and the northern part of Wyoming Territory; the Department of Texas, comprising the State of Texas. The Division of the Pacific comprises the Department of California, States of California and Nevada; the Department of Arizona, Territories of Arizona and New Mexico; and the Department of the Columbia, States of Oregon and Washington, and Territories of Idaho and Alaska.

Millennium. The idea of the Millennium, literally a thousand years' time, originated proximately in the Messianic expectation of the Jews; but more remotely, it has been conjectured, in the Zoroastrian doctrine of the final triumph of Ormuzd over Ahriman, and was connected by the Christians with the second coming of Christ. The notion of a golden age, preserved by the converts from heathenism to Christianity, as well as the oppression and persecution to which they were long subjected by the state authorities, were naturally calculated to develop and strengthen such hopes. The chief basis of the millennium idea in Judaism as well as in Christianity, however, is the ardent hope for a visible Divine rule upon earth, and the identification of the Church with that of which it is merely a symbol. In the Mosaic account of creation we find the primitive ground for making the victorious era of the Church last a thousand years. By a strictly literal interpretation of the 4th verse of the 90th Psalm it was supposed that a day of God was arithmetically equal to a thousand years; hence the six days of creation were understood to indicate that the earth would pass through 6,000 years of labor and suffering, to be followed by a seventh day-that is, 1,000 years of rest and happiness. In the Book of Revelation this view is presented. Still, the rabbinical traditions differ widely among themselves as to the durarion of the happy period. During the civil and religious wars in France and England the belief in millenniumism was prominent. The Fifth-monarchy men of Cromwell's time were millennarians of the most exaggerated and dangerous sort. [See Fifth-Monarchy Men.] Their peculiar tenet was that the millennium had come, and they were the saints who were to inherit the earth. Great eagerness and not a little ingenuity have been exhibited by many persons in fixing a date for the commencement of the millennium. The celebrated theologian Johann Albrecht

Bengel asserted, from a study of the prophecies, that the millennium would begin in 1836. This date was long popular. Swedenborg held that the last judgment took place in 1757, and that the new Church, or "Church of the New Jerusalem," as his followers designate themselves in other words, the millennium era-then began. In America considerable agitation was excited by the preaching of one William Miller, who fixed the second advent of Christ about 1843. Of late years the most noted millennarian was Dr. John Cummings of England, who originally placed the end of the present dispensation in 1866 or 1867; but as the time drew near without any millennial symptoms he was understood to have modified his views considerably, and came to the belief that the beginning of the millennium will not differ so much after all from the years immediately preceding it, as people commonly suppose.

Mineral Veins were Filled, How.-The latest theory, and the one generally accepted by the best-informed students of science as to the manner in which the minerals of the earth have been deposited in veins, is that the deposition of mineral matter is due to chemical precipitation. According to this theory, the fissures are first filled with water, usually flowing from sources deep in the earth, where, highly heated and under great pressure, it becomes charged with mineral substances. As it approaches the surface, and the temperature and pressure are reduced, the minerals which it had in solution are precipitated on the sides of the channel. The extensive deposits of various minerals on the walls of thermal springs seem to show that this theory is sufficient for mineral veins. Water or steam, holding in solution sulphur, fluorine and chlorine, and highly heated, might dissolve any minerals with which it came in contact. The formation of geodes and of stalactites in caves seem to prove that solutions of mineral matter are constantly flowing through the rocks beneath the surface of the earth. Out of the numerous theories that have been advanced in explanation of this matter there are four others which are worthy of note-the theory of injection, of aqueous deposition, of lateral secretion, and of sublimation. The theory of injection was held at the time when philosophers were accustomed to ascribe all the great changes in the earth's surface to the action of heat. It should be noted, however, that there are very few mineral veins whose materials can be regarded as even the possible product of fusion, and most of them contain minerals that never could have been formed in the presence of great heat. When the veins on the south shore of Lake Superior, which contain great masses of copper, were first described, they were considered as remarkable examples in proof of the igneous theory; but as masses of native silver are formed in these copper veins, both metals being distinct and nearly pure chemically, it was plain that the veins could not have been filled by the action of heat, as these metals in that case would have united in the form of an alloy.