and, when the mixture has cooled, place 100 grains of fine cotton wool in a Wedgwood mortar, pour the acid over it, and with a glass rod imbue the cotton as quickly as possible with the acid; as soon as the cotton is completely saturated, pour off the acid, and with the aid of a pestle quickly squeeze out as much of the acid as possible; throw the mass into a basin of water, and thoroughly wash it, either in successive portions of water, or underneath a tap, until the cotton has not the slightest acid taste; finally squeeze it in a linen cloth, and dry it in a water bath. Mr. Hadow obtained the best results by mixing 89 parts by weight of nitric acid (sp. gr. 1.424) with 104 parts by weight of sulphuric acid (sp. gr. 1.833). The sulphuric acid has no direct action upon the fibre; its effect is to take up the water from the cotton and prevent the nitric acid from dissolving the compound, which it does in part when employed alone. Prof. Ellet steeped the cotton in a mixture of nitre and sulphuric acid. The cotton is not altered in appearance by being subjected to this process, but it has gained about 75 per cent. in weight, and has acquired several new properties. It is harsh to the feel, and crepitates when pressed in the hand. It is electrically excited by drawing the fibres through the fingers. When freshly prepared with particular care it is soluble in ether, and forms the adhesive liquid already described under COLLODION. If this solution be poured upon cold water, the ether evaporates and leaves an opaque film, which taken off and dried is an explosive paper. At the temperature of 370° F., or lower according to Dr. Marx, gun cotton explodes, but it produces so little heat that a wisp of it may be ignited in the open hand without injury; and if upon a heap of gunpowder it is carefully brought to the explosive temperature, it may flash off without firing the powder. When confined it exerts in exploding a much greater power than gunpowder, but so instantaneously that it is not found applicable to the purposes served by the latter material. Guns are liable to be burst by it before the exit of the ball can give room to the expansive force of the gases produced; and in blasting, the rock is not shaken by it at a distance from the charge. Its action is too much like that of the fulminates to admit of the useful applications at first anticipated. It is like these, moreover, exceedingly dangerous to prepare and keep in any consider able quantity, and is open to the further objection of rapidly absorbing moisture from the atmosphere to the extent of nearly its own weight, which must be expelled by drying before the material can be employed. It also decomposes spontaneously when kept for some time. The products of its combustion are carbonic acid, water, and nitrogen, and, when not very carefully prepared, nitrous acid also. This and the water are opposed to its use in fire-arms. Its freedom from smoke would strongly recommend its use in mines, but its cost compared with that of gunpowder, and the other objections named,

have caused it, after several trials in different countries, to be given up. The composition of gun cotton has been commonly expressed by the formula of Pelouze, C24 H17 O17, 5NO5, which corresponds to an increase in the weight from that of the raw cotton of 75 per cent.; and Pelouze found that this increase was constantly from 74 to 76 per cent. Other chemists, however, obtained different results; the increase of weight being variously stated from 65.4 per cent. to double the original amount. The most elaborate experiments have been made by Mr. Hadow. He found that the product varied materially with the strength of the acid, and that the water in the cotton also served to modify the composition of the product. With acids of variable strength he obtained compounds ranging in increase of weight from 40 per cent. upward; but with a repeated immersion in acid of the strength proved to be the best, he concluded that there were at least 3 definite compounds, one represented by an increase of 64 per cent. in weight, one by 72, and one by 82.

GUN-SHOT WOUNDS, injuries caused by the discharge or bursting of fire-arms, consisting of severe contusions with or without solution of continuity. They are of two classes, according as the explosion of the powder does or does not carry solid projectiles. Slight wounds from powder alone are properly burns; but if the quantity of powder be large or in a confined space, serious and fatal contusions and lacerations may ensue; not only the expansion of the liberated gases, but the unburned portions of powder, and the contact of surrounding bodies put in motion by the explosion, of wads, and of pieces of burst weapons, are to be considered in these complicated wounds, though their treatment is ordinarily the same as for burns, lacerations, and contusions from other causes. These wounds are purely mechanical, and not poisoned, as was formerly supposed; of course they are more dangerous in proportion to the contiguity to vital organs; an explosion from a pistol introduced into the cavity of the mouth or near the thoracic or abdominal cavity might prove fatal, while the same on the back or limbs would be of trifling moment. A wound from a musket ball in a fleshy part presents an opening of entrance, smaller than the ball in most cases, and with livid and inverted edges, and the opening of exit, if there be such, larger, more ragged, and with everted edges; if the ball was fired very near, the entrance is larger than the exit; the importance of these facts in legal medicine is evident, as it often enables an expert to tell the direction and the distance from which a wound was received; the diminished velocity of the ball, its more rapid rotation on its axis, and its consequent more lacerating progress, explain the larger and more irregular opening of its exit. A very slight obstacle is sufficient to divert a ball from its original direction, causing singular eccentricities in its course; a trifling obliquity of surface,

or difference of density in the parts struck, may produce the most circuitous passage; the records of military surgery show that a ball may enter on one side of the head, neck, chest, abdomen, or limbs, and pass out on the other, having apparently passed directly through, whereas it has really passed entirely round; many of these cases are very curious and almost incredible. Spent balls cause injuries of great violence and with little apparent external wound; these cases were formerly attributed to the wind of the ball, from compression or displacement of air in its course; it is now known that a ball after a certain period of its course, from the resistance of the air, the attraction of the earth, and other causes, acquires a rotatory motion on its axis, the more rapid as its progress is nearly ended; if a ball with such a motion strike a part of the body, it does not pierce or carry it away, but simply rolls over it like a wheel, crushing the unyielding and resisting tissues, without necessarily lacerating the skin -contusing the viscera, for instance, without opening the abdominal cavity. A ball in its course may meet and force into the body pieces of clothing, bone, or other foreign bodies, more mischievous than the original projectile. The pain of a gun-shot wound is dull and heavy, and by no means so inconsiderable at the moment of infliction as is generally supposed, though in the excitement of battle it would be less noticed than a sabre or bayonet wound. The bleeding is generally less externally than would be supposed, unless a large artery be severed, as in other lacerated and contused wounds. The constitutional disturbance is great and peculiar; the paleness and coldness of surface, trembling and weakness of limbs, faintness, alarm, and confusion of mind, are more marked than in other kinds of wounds of equal severity. In common cases, inflammation comes on in the course of 24 hours, with swelling, stiffness, and pain; pus forms on the 3d or 4th day, and in the course of the next 5 days more or less of the parts torn by the ball slough away; this over, granulations form, the wound contracts, and heals in 6 or 8 weeks, the lower opening closing first. In healthy persons the constitutional disturbance is neither great nor of long duration. In unhealthy constitutions, and after improper applications or the unavoidable exposures of a campaign, inflammation runs high, the suppuration is profuse and obstinate, and even after long contiuued treatment the patient recovers with a disabled limb or an enfeebled body. If the ball or foreign body carried with it enters a sensitive or vital part, there will be no ease nor safety until it comes away; but if it enters parts without much sensibility and presses upon no nerve, it may remain for years without inconvenience. Mortification of a limb after a gun-shot wound may arise from the severity of the wound, the excess of inflammation, or division of the large blood vessels. Another dangerous complication of these wounds is secondary hæmorrhage from

excess of arterial action, separation of sloughs from arteries, ulceration of their coats, or general inflammatory exudation; this is most likely to occur in persons of sanguine temperament, when exposed to the depressing influences of hospital life. The prognosis in these wounds should be given with much reserve, as it is impossible in most cases to predict the exact result; if the thoracic and abdominal cavities or the joints are penetrated, or any important organ is wounded, with injury of large vessels or nerves, or comminuted fracture of bones, the danger of a fatal termination is great. The experience of the battle field, and unfortunately of civil life in our large cities, affords remarkable instances of survival for several days after the most frightful injuries and wounds of vital or gans; to mention from the latter only two instances, one yet fresh in the mind of the public-the pugilist Bill Poole of New York lived for some time with a ball lodged in the substance of the heart, and Virginia Stewart, a woman of the town in the same city, lingered for several days after a pistol bullet had passed through her brain. The wounds made by the conical balls sent from the recent improved rifles are attended with more than usual laceration of soft parts and splintering of the bones, and the consequent relative fatality in war is considerably greater than with the old muskets. After death from these wounds, caused by a fatal shock to the nervous system when any vital organ is penetrated, a remarkable flaccidity of the muscles and serene expression of countenance are generally noticed; the wound is either too benumbing, or the death too sudden, to permit the agony of dissolution and its accompanying ghastliness and rigidity.--The treatment of simple gun-shot wounds does not ma terially differ from that of lacerations and deep punctures. Cleansing of the openings, the arrest of hæmorrhage, stimulants and opiates, antiphlogistic and soothing applications, free exit of pus, and rest of the part, are the principal points to be attended to; if there is but one opening, search should be made, by dilatation if necessary, for the ball or other foreign body, which should be extracted if it is likely to prove inconvenient or dangerous; secondary hæmorrhage will require compression, cold, caustic, or the ligature, according to circumstances. In cases of severe laceration with splintering of bones, the question of primary or secondary amputation becomes one of the most difficult the surgeon has to decide; military surgeons differ on this point, though the weight of authority and experience is in fa vor of primary amputation, choosing the medi um between those who let the knife follow the shot and those who delay till the patient is nearly exhausted by pain, previously ascertaining that there are no other fatal injuries. The treatment of complications must be conducted on the general principles applied to similar conditions from other causes. When small shot are fired into the body from a considerable dis

tance, they are much scattered and near the surface, and may generally be picked out with a cataract needle; when the discharge has been very near the person, the shot, entering in a compact mass, produce a lacerated wound requiring the same treatment as for a bullet. Grains of powder may be picked out one by one, and the discoloration much diminished by the constant application of olive oil. The excitement of an eczematous inflammation on the skin by a corrosive sublimate solution has, according to Prof. Busch, been found efficacious in detaching the granules of powder from recent burns. In wounds from cannon shot, the question is generally that of amputation, and its treatment and consequences. In military hospitals, the sequelae of gun-shot wounds, traumatic fever, hospital gangrene, phlebitis, abscesses, and exhausting suppurations, destroy many who would recover in civil practice.

GÜNDERODE, KAROLINE VON, a German poetess, born in Carlsruhe in 1780, died in 1806. She became canoness of a chapter in Frankfort-on-the-Main, and under the name of "Tian" wrote a number of poems remarkable for passionate feeling and facility of language. Of a sensitive and impressible disposition, she conceived, it is said, an attachment for the philologist Creuzer, the unhappy result of which induced her to put an end to her life by stabbing herself through the heart. She was on terms of great intimacy with Bettina von Arnim, who has published their mutual correspondence, under the title of Die Günderode (2 vols., Grünberg, 1840); translated by Margaret Fuller (Boston, 1842). Her literary remains consist of Gedichte und Phantasien (Hamburg, 1804) and Poetische Fragmente (Frankfort, 1805). Her Gesammelte Dichtungen was edited by Fr. Götz and published in Mannheim in 1857.

GUNDUCK, a river of Hindostan, which rises N. of the Himalaya mountains, and, after cutting a passage for itself through that chain, flows in à S. E. direction to Kajeepoor, where it falls into the Ganges, in lat. 25° 39′ N., long. 85° 16' E. Its course is estimated at 400 m. The scenery, at its emergence from the Himalaya range, is magnificent. The river banks are either precipitous cliffs or forest-clad flats, while in the distance are seen through the vistas the snow-crowned summits of stupendous mountain peaks. In the upper part of its course it is called Salgrami, from a singular species of stones found in its channel, and held sacred by the natives; they are mostly round, and are generally perforated in one or more places.

GUNDWANA, an imperfectly defined tract of S. India in the Deccan. It may be said to lie between lat. 19° 50′ and 24° 30′ N., long. 77° 38' and 87° 20′ E., and to comprise the British districts of Saugor and Nerbudda, Chota Nagpoor, Sirgooja, Singrowli, part of Nagpoor, the Cuttack Mehals, &c.; length about 400 m., breadth about 280 m. The climate is unhealthy. The surface is in general mountainous, ill watered, and covered with jungle. The Gonds or Koonds, VOL. VIII.-37

the hill tribes, who took refuge in its mountains and fastnesses from the invaders of the more fertile regions, are supposed to be the aborigines of Hindostan. They are a savage, marauding race, who frequently descend upon the plains and plunder the occupants. They are Brahmins, but abstain from no flesh save that of the ox, cow, and bull. The more fertile tracts of Gundwana were subdued at an early period by the Mahrattas, and made nominally tributary, but it was found impossible to collect any revenue from the vanquished people without undertaking a regular campaign for that purpose. Portions of it were annexed to the Anglo-Indian empire in 1818 and 1853. The rest is also under British control.

GUNNERY, the science of regulating and directing the motions and effects of projectiles from guns. The theory of the motion of a body projected in free space, either parallel to the horizon or in an oblique direction, by the force of gunpowder, is very simple, and rests upon this single consideration: that while the body moves forward by the impulse given to it, it is at the same time constantly descending toward the ground through the force of terrestrial gravity; and as terrestrial gravity is uniform, and constantly the same at all places at nearly the same distance from the centre of the earth, the body descends by a force that acts constantly and equally. By these two motions the body is carried over a certain space in a perpendicular direction, while it is carried over a certain other space in a horizontal or oblique direction, and by the composition of these two motions the real path of the projectile becomes a curve. But the mathematical relation of these two spaces to each other is that relation which constitutes the property of the parabola; the path of a body projected into free space by the force of gunpowder, therefore, is the parabolic line. There are two propositions which embrace the general theory of projectiles; one is, having the direction and initial velocity, to determine the greatest height to which the projectile will rise, and its random or horizontal range; the other is, with the same data to determine the range on an oblique plane. Before, however, applying these two proposi tions, and the theorems deduced from them, to the practice of gunnery, it is necessary to have recourse to experiment for information upon various subjects connected with the explosion of gunpowder, and the discharge of projectiles. So entirely inapplicable are the theorems without such experiments, that it must be candidly admitted that they are of no practical value except in cases where the velocity of the projectile does not exceed 500 feet a second; and even here they give only an approximation to the truth. The enormous resistance made by the air to all projectiles moving with any considerable velocity renders useless the most elaborate investigations of the modern analysts, who, according to Dr. Hutton, have assumed a very erroneous law of resistance in their calculations.

ferred, attracted the attention of the celebrated Euler, and was translated into French and published by Lombard in 1783. Previous to this, however, MM. D'Arcy and Le Roy had applied the ballistic method of Robins, with some ingenious changes in the means of measuring the arc described by the pendulum, to a large number of experiments, which they published in the "Memoirs of the Academy of Sciences" in 1751. It was with the help of the same method that D'Arcy made the subsequent experiments, of which he gave an account in his Essai d'une théorie d'artillerie, published in 1760, where also are found numerous results of the variations in the initial velocity of the ball depending upon the length of the piece. The block of the pendulum used by D'Arcy was of steel, and his balls were made of lead. But of all who took up the subject in the last century, no one accomplished so much as Hutton, who continued up to 1791 the experiments he had begun in 1775. He changed the weight of the pendulum, the size of the ball, and the charge of powder, so as to give great range and variety to his investigations, all of which are published in his "Tracts on Mathematical and Philosophical Subjects" (3 vols. 8vo., London, 1812), and continue to constitute the text book of the student. The experiments comprised in the years 1783 to 1786 were translated into French, and published in 1802 under the title of Nouvelles expériences d'artillerie, by Col. Villantroys; those of 1787 to 1791 were published under the same title in 1826 by M. Terquem. In 1815 Dr. O. Gregory, mathematical master, and afterward professor, in the military school at Woolwich, constructed a pendulum weighing 7,408 pounds, nearly 3 times as large as the largest used by Hutton, upon which he practised with a 24-pounder. He combined the two separate methods employed by Hutton and D'Arcy for measuring the arc of oscillation at the upper and lower parts of the pendulum; and in order to obtain the exact centre of percussion of the ball upon the block, the front surface of the latter was covered with a sheet of lead. Curious details concerning this enormous structure, and some of the results it led to, may be found in the Annales de physique et de chimie, and the Voyage dans la Grande Bretagne of M. Charles Dupin. Another method has been employed, though comparatively little, for determining the initial velocity of projectiles; that is, rotating machines. Antoni, who attributes the invention to a mechanic named Mattei, was the first to make use of it. He gives an account of his experiments in his Esame della polvere (Turin, 1765, translated into French by M. de Flavigny in 1773). The machine used by Antoni consisted of a horizontal circle, supported at the centre upon the upper extremity of a vertical axis, and answering as a stand for a cylindrical envelope of paper; the rotary motion is given to this cylinder by means of a weight attached to a cord which passes over a fixed pulley. In 1803 Col. Grobert proposed a machine

in which he substituted in the place of the cylindrical surface of paper two disks or circles of pasteboard, arranged perpendicularly on the same axis passing through their centre. This apparatus, employed by the members of the institute charged with its examination, in making some experiments upon the initial velocity of musket balls, was put in motion by the same means as the instrument of Mattei. Finally, Dr. Gregory, while he adopted the disks of Col. Grobert, substituted for the weight that gave motion to his instrument a spring enclosed in a barrel similar to that of a watch, which communicated to the disks by means of toothed wheels an equal and regular motion. This brief historical summary is sufficient to give an idea of the labor that has been bestowed upon the problem of the initial velocity of projectiles, and of the importance attached to its solution; and it will be useful to introduce here an explanation of that term. The effects of artillery are produced by means of 3 principal bodies-a gun, a charge of powder, and a projectile. The powder, or rather the elastic fluid disengaged in the combustion of the powder, is the agent; the projectile is the resistance put in motion; and the gun is the machine by means of which the agent acts. Now, the force exerted upon the ball during the time it is in the gun gives rise to the term initial velocity, which is in fact the space the ball would pass through in a unit of time, and in a direct line, at the moment of leaving the mouth of the gun, if nothing interfered to change its motion. Of all the questions relating to artillery, this of the initial velocity is practically the most important. The knowledge of it is indispensable in order to form a correct estimate of the effect of the projectile, and to determine the amount of powder necessary to produce this effect. Between the years 1842 and 1846 experiments were made at L'Orient with the gun and ballistic pendulums; and in 1843 a similar series was made at Washington under the direction of Major Mordecai. The cannon pendulum and its ballistic pendulum, used by Major Mordecai, were made, with some modifications in the details, on the plan of those recently erected at Metz, in France. "The principal conditions to be fulfilled in the arrangement of these pendulums were: 1, that the pendulum block should be capable of sustaining without injury the impact of balls of large calibre moving with great velocity; 2, that the core or part of the block which receives the impact of the ball should be susceptible of being easily and quickly renewed after each fire; 3, that the frame of the gun pendulum should be capable of receiving guns of various calibres; 4, that arrangements should be made in each pendulum for adjusting the height of its centre of oscillation, so as to make it coincide with that of the line of fire, in order to prevent violent shocks on the axis of motion; 5, that the apparatus should not be liable to be affected by hygrometric changes in the atmosphere." For a detailed description of the manner in which