atural law, e. g., to murder, or mala in se, as well as to crimes artificially created by the policy of the particular state, mala prohibita; and it is now said that the case of Don Pantaleon Sa, the brother and secretary of the Portuguese ambassador, who was executed for an atrocious murder during the protectorate of Cromwell in 1654, was no exception, as he was not joined with his brother in the same commission.' See AMBASSADOR, EMBASSY. The arrangement of international ceremonies belongs to the subject of diplomacy. To treat it in detail would lead us far beyond our limits, and we must content ourselves with remarking a few of the customary and conventional modifications which affect the general principle of international law by which all independent states are held to be equal.

Royal honours are enjoyed by the empires and kingdoms of Europe, including the Swiss Confederation, the grand duchies of Germany, and, amongst Catholic states, by the pope; and the same right extends to the United States of America. These, along with other rights of greater importance, include the right of taking precedence of the others in all international ceremonials. Amongst those who enjoy royal honours, the order of precedency, after much discussion, was left by the Congress of Vienna on the ancient footing of custom merely. The rule thus fixed is said to be the following: Monarchs enjoying royal honours, but not crowned heads, yield precedence to those who are, whilst they enjoy it over all other monarchs, demi-sovereigns, and rulers of dependent states. This rule leaves the relative rank of the crowned heads and other classes amongst themselves undetermined, and a curious expedient has been found for obviating the necessity of a minuter classification. By what is called the alternat, the rank and places of the various powers are changed from time to time in a certain order determined by lot. If there are several parties to a treaty, for example, a corresponding number of copies is made of it, the name of each state being named first in the copy which it preserves, and the others in the order determined by the alternat. But the right to alternation has sometimes been a subject of contention. In 1742, it was refused to Prussia by Great Britain; and Hungary and Sardinia had great difficulty in obtaining it at the peace of Aix-la-Chapelle.

The subject of maritime ceremonies will be treated under its respective heads. They consist of salutes either with cannon, or with the flag or pendant, by furling it, lowering it, or pulling it down. There is also a salute with sails, which generally consists in lowering the foretopsail. Maritime ceremonials are usually made the subject of express compact, but, as a general rule, on the open seas, a ship carrying a pendant salutes a ship of a friendly power carrying an admiral, and detached ships generally salute fleets. It is provided by 22 and 23 Vict. c. 5, repealing in so far 6 Anne, c. 7, that pensions granted for diplomatic services, according to the provisions of 2 and 3 Will. IV. c. 116, shall not lisqualify the holder from being elected, or sitting, or voting as a member of the House of Commons.

DIPLOMATICS, the science of ancient writings. The term can scarcely be said to have been at any time in general use in this country, and even on the continent it has latterly given way to the more convenient and descriptive term, PALEOGRAPHY (q. v.).

DIPLO'PTERUS, a genus of fossil ganoid fishes, four species of which have been discovered in the old red sandstone, and two in the carboniferous series. They have heterocercal tails, with double

anal and dorsal fins, opposite each other, but having the dorsal pair a little apart. The head is large and flattened, and the teeth are fewer and larger than in the allied genera. The scales are perforated with small foramina.

DIPPEL'S ANIMAL OIL, called also Empyreumatic Animal Oil, or Rectified Oil of Hartshorn, is prepared by the destructive distillation of bones in close vessels, when BONE-BLACK (q. v.) is left in the retort or vessel, and the crude oil distils over into a suitable receiver. Wher obtained in this manner, it is a thick viscid oil of a brown colour, and a very disagreeable odour, but on redistillation it may be obtained limpid and colourless. Air and light affect the pure or rectified oil, and render it coloured and somewhat viscid. Its elementary constituents are carbon, hydrogen, nitrogen, and oxygen, and it contains a number of volatile organic bases, such as aniline, picoline, &c. Dippel's animal oil is a powerful medicinal agent, and when swallowed in doses of a few drops, it is antispasmodic, and stimulates the vascular and nervous systems. In large doses, it is a powerful irritant poison.

DIPPER (Cinclus), a genus of birds of the Thrush family (Merulidae), distinguished from the other birds of that family by an almost straight, compressed, sharp-pointed bill, and still more by their manners and habits. They frequent clear pebbly streams and lakes, feeding chiefly on molluscs and on aquatic insects and their larvæ, which they seek even under water, diving with great facility, and moving about for a short time at the bottom of the water. They carry their rather short tail elevated after the manner of wrens, which they also resemble in their 'frequent becks' or dipping of the head, accompanied with an upward jerking of the tail. One species is found

in Britain, the COMMON D., or WATER OUSEL (C. aquaticus), a bird rather smaller than any of the British thrushes, of a generally dark-brown colour, with throat and upper part of the breast pure white. It is found throughout the whole of Europe and the north of Asia, but chiefly in hilly or mountainous districts. It is not gregarious. The D. stone in the midst of or beside the stream, its never fails to attract notice, as it sits upon some white breast rendering it conspicuous as it repeats the movement from which it derives its name. It builds a very curious nest of interwoven moss, domed and with the entrance in the side, usually in some mossy bank close by a stream, and often near or under a cascade. The assertion which has been made, that the D. walks without apparent muscular effort at the bottom of the water. is

incorrect; its feet are not well formed for walking, and it moves under water by means of its wingswhich are short-not without much muscular effort. The statement also often made, that it eats the spawn of salmon and other fishes, in the belief of which it is much persecuted in Scotland, although not improbable, is not sufficiently authenticated. Other species of D. are found in Asia and North America.

a

S

or

DIPPING-NEEDLE. If a magnetic needle be supported so as to be free to move vertically, it does not at most places on the earth's surface rest in a horizontal position, but inclines more less from it. If the vertical plane in which 6 the needle moves is the magnetic meridian of the place, the angle between the needle and the horizontal line is called the dip or inclination of the needle. Thus, if the needle, NS, be supported at its centre, C, so as to be free to move vertically, the plane of the paper being supposed to be that of the magnetic meridian, the angle NCa is the dip. The dip of the magnetic needle at any place can be ascertained with very great exactness by means of the dipping-needle, fig. 2. It consists of a graduated circle, AA, fixed vertically in the frame FF, and moving with it and the vernier V, on the horizontal

N

Fig. 1.

graduated circle HH. This last is supported by a tripod furnished with levelling screws. At the centre of the circle, C, there are two knife-edges of agate, supported by the frame, and parallel to the plane of the circle. The needle, NS, rests on these knife-edges by means of two fine polished cylinders of steel, which are placed accurately at the centre of the needle, and project at right angles from it so adjusted, the needle moves with little or no friction. It is so made, moreover, that before being magnetised it remains indifferently in any position; after magnetisation, therefore, the dip which it shews is wholly due to the magnetic influence of the earth.

In order to understand how an observation is made with the dipping-needle, we must regard the directing

force of the earth's magnetism exerted upon the poles of the needle in any vertical plane in which it may happen to be, as resolved into two forces, one acting at right angles to the plane, and the other acting in the plane. There being a corresponding but opposite force at each pole, we have thus two statical couples acting on the needle-one tending to turn it at right angles to the plane in which it moves, and the other tending to bring it round to a position in the plane such that the needle and the forces of the couple may be in a line. In the dipping. needle, the mode of support completely neutralises the first of the couples; and the position that the needle takes in any plane is due wholly to the second. When the plane of the needle is at right angles to the magnetic meridian, the forces of this latter couple act vertically, and bring the needle to the same position This, then, gives us the means of determining the magnetic meridian, for we have only to bring the vert.c circle round till the needle stands at 90° to put it a a plane at right angles to that meridian; and then by moving the vernier on the horizontal circle over 90°, we place the upper circle and needle in the plane of the magnetic meridian. The dipping-needle thus serves the purpose of a Declination Needle (q. v.). In bringing the needle round from the plane at right angles to the magnetic meridian, the dip is less and less, till it becomes least in the plane of that meridian. We might thus also find the magnetic meridian, for it is that plane in which the dip of the needle is least. When the needle is in the plane of the magnetic meridian, the couple which acts in other vertical planes at right angles to them disappears, and the whole force of the terrestrial magnetism acts at each pole of the needle, forming a couple which swings the needle round till it stands in a line with itself. The degree on the circle then pointed to by the needle is the dip at the place of observation. Two readings are necessary, for the reason stated in the DECLINATION NEEDLE. One reading is taken, the needle is then reversed so as to change its supports, and then a second reading is noted, and the mean of the two gives the correct reading. The position of the needle when the dip is read off is manifestly the same that a needle suspended in air, if that were possible, and free to move in any way, would finally assume. In resolving, therefore, the total directive force of the earth

as we have done above, we must keep in mind that it always acts parallel to the direction of the dippingneedle.

DIPSA CEE AND DI'PSACUS. See TEAZEL.

DIPSAS (Gr. a kind of serpent), a genus of nonvenomous serpents of the family Colubride, of very elongated form, and with a thick, broad, and obtuse head. They are treesnakes, inhabitants chiefly of the warm parts of Asia and America. One species only, D. fallax, somewhat doubtfully referred to this genus, occurs in the south of Europe. Some of the species are of great size. The figure represents a large and beautiful species found in Java and Sumatra. The form is more attenuated than in others of the genus.

Dipsas cyanodon.

DIPSOMA'NIA, or OINOMA'NIA, from the Greek words dipsa, thirst, or oinos, wine, and mania -terms of modern invention, to denote an irresistible or insane craving for alcoholic stimulants, when occurring in a habitual or confirmed form, and requiring confinement or restraint of the person for its cure. Much discussion has taken place in regard to this and other forms of what is often called Moral Insanity; the most recent views of physicians, however, tend to shew that the drinking insanity, or furor bibendi, as it was called by an early writer on the subject, is often associated with other forms of mental derangement, and is very apt to be, in connection with one or more of these forms, hereditarily transmitted, even through several generations; so that the really physical or insane character of the craving for stimulants, at least in some cases, may be regarded as a well-established fact in medicine. The legal and general questions in connection with this subject will be discussed under the heads of INSANITY and INTEMPERANCE. DIPTERA (Gr. two-winged), an order of insects, which received from Aristotle the name it still bears. Its distinguishing characters are so obvious that it has been acknowledged, with little change of its limits, by almost all naturalists. FLY is a popular name very generally applied to dipterous insects, and often with some distinguishing prefix (as House-fly, Flesh-fly, Blow-fly, Bot-fly, Crane-fly, &c.), although it is sometimes used with such prefix to designate insects not belonging to this order (Dragon-fly, Dayfly, May-fly, &c.). Midges, gnats, and mosquitoes are also dipterous insects. In the number of species which it contains, this is one of the most extensive orders of insects: some of the species are also remarkable for the immense multitudes in which they appear; and although most of them are of small size, and few attract us by brilliant hues, not a few are important on account of the annoyance or mischief which they cause, either in their perfect or in their larva state; whilst many of their larvæ (maggots) are also very useful in consuming putrescent animal matter, which might otherwise prove a source of pestilence.

The D. have only two wings, which are membranous and simply veined. A little behind the wings are two small slender organs called Halteres, poisers, or balancers, the use of which is not well known. They are usually present even in those exceptional insects of this order in which the wings are not developed. The head of the D. is generally in great part occupied by the large compound eyes, which often contain thousands of facettes; and besides these, three simple or stemmatic eyes (ocelli) are often also present, placed upon the crown of the head. The mouth is formed exclusively for suction, and is usually furnished with a short membranous suctorial proboscis, composed of parts which represent, although so differently modified, the portions of the mouth in coleopterous and other masticating insects, some of the parts, however, often disappearing. The proboscis of my is capable of piercing the skins of animals n the juices of which they feed; others are quite destitute of this power of piercing. Many feed chiefly on saccharine and other vegetable juices. In some genera, the perfect insect seems destitute of a mouth; and the term of life, after the perfect state has been attained, very brief in some, appears to be brief in all. The power which many dipterous insects possess of walking even on very smooth surfaces, in any position, even with the back downwards, familiar to every one in the example of the common house-fly, has not yet received a sufficient explanation. The opinion that their feet are furnished with discs for the formation of a vacuum, has been

called in question, but nothing satisfactory has been substituted for it. The terminal rings of the abdomen in the females of many species, form an ovipositor capable of piercing the substances in which the eggs are to be laid, and composed of pieces which may be exserted or retracted into one another like those of a telescope. The eggs are very generally deposited in putrescent animal substances, but those of some kinds in the bodies of living animals, some in vegetable substances; the larvae of some live in water; the eggs of a few are hatched within their own bodies, and the larvæ of some even remain there till they pass into the pupa state. All the D undergo a complete metamorphosis. Their larva are destitute of true feet, although some of them have organs which serve for the same purpose; some have a distinct head; but others have the head soft and changeable in form, capable of being retracted into the body, and distinguishable only by its position, and by the organs of the mouth. Those which dwell in water or in fluid putrescent matters, have a retractile tail-like prolongation of the body, terminated by a radiated expansion, which communicates with air-tubes, and constitutes part of a very remarkable respiratory system. larvæ of some D. spin cocoons when about to pass into the pupa state; but in others, the skin of the larva hardens and encases the pupa; the perfect insect finally making its escape by forcing off with its head the end of its pupa case.

The

DIPTERA CEÆ, or DIPTEROJARPA'CEÆ, a natural order of exogenous plants, consisting of beautiful and majestic trees, natives of the East Indies. Some trees of this order, of which about fifty species are known, are highly valuable as timbertrees. Among them is the SAL (q. v.), the most esteemed timber-tree of India. They abound also in balsamic resin, and their resinous products are used for a variety of purposes. See ÁNIME, CAMPHOR, COPAL, DAMMER, PINY VARNISH, and SAL.

Dipterocarpus, the genus from which the above order has received its name, contains several species of the noblest trees of India. They abound in the and the Eastern Peninsula. The wood is used for warm parts of the east coast of the Bay of Bengal house-building, ship-building, &c. D. turbinatus, the GURJUN or GOORJUN TREE, the species by which the genus first became known, often attains a height of upwards of 200 feet, and a girth of 15 feet. It has a pale-gray trunk, rising without a branch till it forms at its summit a small symmetrical crown. The leaves are broad, glossy, and beautiful; the flowers in white racemes, but not conspicuous. The wood is hard, close-grained, and durable. A fragrant oil exudes from the trunk, which is extremely valuable for pitch and varnish, and is also used medicinally. It is procured by cutting transverse holes in the trunk, pointing downwards, and lighting fires in them, which causes the oil to flow. The tree is sometimes called the WooD-OIL TREE. This oil or balsam is also procured from other species of Dipterocarpus. D. trinervis yields a resin which is valuable for plasters, and acts on the mucous membranes like Balsam of Copaiva. The Javanese smear banana leaves with this resin, which then burn as torches, with a pleasant odour and white light.

DI'PTERUS, a genus of fossil ganoid fishes, peculiar to the old red sandstone, in which two species have been found. They derive their name from their most striking characteristic-the double anal and dorsal fins, which are opposite to each other. The head is large and flattened, the teeth subequal, the scales perforated by small foramina and the tail heterocercal.