Galt.

bling the doctrines of the Scotch school as amended by Hamilton. His systematic work, Elementi di Filosofia, was long used as a text-book for instruction in the Italian colleges. G., though in many respects Kantian, can hardly be said to have fully taken up the speculative significance of the Critique of Pure Reason. He accepts the Kantian demonstrations of the necessary unity of consciousness as the indispensable factor in knowledge, regards our knowledge of the ego as knowledge of substance, maintains that in external perception, or, as he puts it, in sensation, we are directly cognizant of the real thing, and holds that the existence of the unconditioned is given in knowledge as the necessary correlate of the conditioned, but rejects entirely the a priori element which is the distinguishing characteristic of the Kantian doctrine of cognition. All judgments, according to him, are ultimately identical. On the other hand, G. exagge rates the place and importance of the moral reason; with Kant, he finds objective truth in the ideas of desert and duty, and admits that ethical judgments are a priori, without endeavoring to explain, in accordance with his theoretical views, how such judgments are at all possible.

GALLUS, C. CORNELIUS, B.C. 66-26; a Roman poet, orator, and politician, b. in Gaul, of humble origin. Going to Rome he was taught by the same master as Virgil and Varius. In political life, he espoused the cause of Octavianus, and as a reward for his services was made prefect of Egypt. His conduct in this position afterwards brought him into disgrace with Augustus; and, dreading the exposure of his arrogance, extortion, and cruelty, he put an end to his life by throwing himself on his sword. G. acquired among his contemporaries a high repute for intellect. He associated on terms of equality with Virgil, Ovid, Varius, Asinius Pollio, and others; and on account of his four books of elegies, Ovid claimed for him the first place among the elegiac poets of Rome. His fame as an orator was hardly inferior to his renown as a poet; but not a fragment of his composition has descended to our times.

GALOCHES. See GOLOSHES.

GALOIS, EVARISTE, 1811-32; a French mathematician. Much of his attention was devoted to researches on the resolubility of algebraic equations by radicals. But these researches, crowning as it were the previous labors of Lagrange, Gauss, and Abel, have in a signal manner advanced the theory, and it is not too much to say that they are the foundation of all that has since been done, or is doing, in the subject. The fundamental notion consists in the establishment of a group of permutations of the roots of an equation, such that every function of the roots invariable by the substitutions of the group is rationally known, and reciprocally that every rationally determined function of the roots is invariable by the substitutions of the groups. As part of the theory (also the investigation has a very high independent value as regards the theory of numbers, to which it properly belongs), Galois introduces the notion of the imaginary roots of an irreducible congruence of a degree superior to unity. He was killed in a duel.

GALT, a thriving t. of Canada, in the co. of Waterloo, province of Ontario, principally built of stone. It stands on both sides of the Grand river, about 55 m. from its entrance into lake Erie. The eastern and western parts of the town are connected by two wooden bridges, resting on massive stone piers. The environs of the town are noted for their beauty. The first house of G. was built in 1816, amid a dense forest of pines, which then covered its site. The inhabitants numbered, in 1881, 5,187; the majority being of Scotch descent. It contains numerous places of public worship-Presbyterian, Methodist, Episcopal, Roman Catholic, and Baptist. It supports one grammar and one common school; the average attendance of the latter being about 500; and has an extensive library and public reading-room in connection with a mechanics' institute. Among its industrial establishments are several woolen manufactories and iron foundries; there are also extensive flour-mills. The manufacture of edge-tools is carried on to a large extent. The trade of the town is greatly promoted by the Great Western railway, a branch of which passes through Galt. The local affairs of G. are managed by a mayor and council of 15 members.

GALT, Sir ALEXANDER TILLOCH, b. England, 1817, son of John, the Scotch author. Alexander became manager of the British-American land company, which he rescued from insolvency and brought to a high degree of prosperity. He was interested in the establishment of the railroad from Montreal to Portland. In 1858, he became minister of finance in the Cartier administration in Canada. In 1862 he resigned, and returned to office in 1864, retiring again in 1866. He was one of the commissioners appointed to promote the confederation of the colonies; high commissioner for C., 1880.

GALT, JOHN, a distinguished Scottish novelist, was b. in Irvine, on May 2, 1779. His father, who was a captain of a ship in the West Indian trade, left Ayrshire in 1780, and fixed his residence in Greenock. In that town, G. received his education, and was then placed in the custom-house. He remained there till 1804, when, panting_after literary distinction, he proceeded to London with an epic poem on the battle of Largs in his portmanteau. On reaching the metropolis, he printed his epic, but becoming dissatisfied with its merits, he ultimately withdrew it from the market. After a few years, his health began to fail, and he was obliged to seek relief in a more genial climate. At Gibraltar, he made the acquaintance of lord Byron-flushed with his first success in the

English Bards and Scotch Reviewers-and his friend Mr. Hobhouse, and the three travelers became fellow-voyagers. Separating from his new friends, G. visited Sicily, then Malta, and finally repaired to Greece, where he again renewed his acquaintance with Byron, and had an interview with Ali Pasha. He then proceeded to Constantinople, and afterwards to the shores of the Black sea. On one occasion, when detained by quarantine, he sketched six dramas, which were afterwards given to the world. On his return, he published Letters from the Levant with considerable success, but first displayed the possession of distinct and individual power in The Ayrshire Legatees, which was published in Blackwood's Magazine in 1820. The Annals of the Parish, a far superior work, appeared the year after, and met with unquestionable success. Having hit on the true vein, he worked it assiduously, and produced Sir Andrew Wylie; The Entail; The Steam-boat; and The Provost, with great rapidity. He then diverged into the walk of historical romance, and published Ringan Gilhaize, a tale of the Covenanters; The Spacwife; Rothelan; and The Omen. These works, although full of striking scenes, and abounding in powerful writing, were not so successful as his earlier and less ambitious performances. G., whose hands were always equally full of literary and commercial undertakings, was now busily engaged in the formation of the Canada company, but before he left England for his distant scene of labor, he gave to the world The Last of the Lairds.

He departed for Canada in 1826, but, disappointed in his expectations, he returned to England in the course of a year or two, and recommenced his literary labors with his usual rapidity. In a short time, he published a novel, Lawrie Todd, which was followed by Southennan, a romance of the days of queen Mary; and this by a Life of Lord Byron, which ran through several editions, but which was roughly handled by the critics. In 1834, he published Literary Miscellanies in three volumes. He now returned to Scotland, utterly broken in health and spirits; and after suffering several attacks of paralysis, he expired at Greenock on April 11, 1839.

G. was a voluminous and unequal writer; but while several of his productions are already forgotten, others of them will perish only with the language. In depicting provincialism, in representing life as it flows on in small towns and villages-communities in which the successful shopkeeper may aspire to be the chief magistrate, and in which the minister is the most important personage-he is without a rival. He has founded a school of writers in Scotland, but as yet his followers have produced no work equal to The Provost or The Annals of the Parish.

GALTON, FRANCIS, b. England, 1822; grandson of Dr. Erasmus Darwin; graduated at Trinity college, Cambridge, 1844; traveled in n. Africa, and on the White Nile, then rarely visited, in 1846, and afterwards undertook the exploration of the western regions of s. Africa in 1850, starting from Walfisch bay. For this journey, of which he afterwards published an account, Narrative of an Explorer in Tropical South Africa, he received the gold medal of the royal geographical society, in whose proceedings he subsequently took an active share, first as member of council, and for several years as one of its secretaries. Mr. Galton is also the author of the Art of Travel, or Shifts and Contrivances in Wild Countries, a work which has gone through numerous editions, and which has been warmly appreciated by travelers and emigrants; also of Meteorographica, the first attempt, on a large scale, to chart the progress of all the elements of the weather, and through which the existence and theory of anti-cyclones was first established by him. He was appointed, on behalf of the royal society, a member of the committee of the board of trade. He has published several works on heredity. He has held office or membership in many scientific societies.

GALUP'PI, BAaldassare, 1706-85; an Italian composer, the son of a barber, educated by Lotti. He wrote an opera when 16 years of age, and it was a failure; but his successful comic opera named Dorinda, produced seven years later, laid the foundation of his fame. He was a prolific writer; no less than 70 of his operas are enumerated, though none have kept the stage. G. resided in London between 1741 and 1744; and afterwards was in St. Petersburg till 1768, as imperial conductor of music, in high honor at the court of the czar. Here he produced his best tragic opera. He is said to have introduced Italian church-music in Russia. In 1768, he resumed his position as organist of the cathedral of St. Marks at Venice, to which he had been appointed in 1762, and which had been kept open for him during his absence. When he died he left 50.000 lire to the poor of Venice. His best comic opera bears the title Il mondo della Luna.

GALVA, a village in Henry co., Ill., on the Chicago, Burlington, and Quincy railroad, where the Peoria and Rock Island road crosses; 141 m. w.s. w. of Chicago; pop. 2,148. It is in a rich agricultural and coal-mining district, on the divide between the Illinois and Mississippi basins. In 1872, nearly the whole village was burned.

GALVA'NI, LUIGI, a famous physician and anatomist, was b. at Bologna, Sept. 9. 1737. At an early age, he evinced a strong inclination to devote himself to a monastic life, and his studies in the university of Bologna were, with this view, chiefly directed to scholastic philosophy, rather than to general science. Swayed, however, by the persuasion of his friends, he relinquished his intention of entering the church, and deter mined to follow the profession of medicine, selecting for special investigation the depart

ments of physiology and comparative anatomy. At this time, he enjoyed the benefit of studying under some of the most eminent medical professors of the day-Beccaria, Tacconi, and Galeazzi, whose talented daughter he subsequently married. So distinguished by his knowledge and ability did he soon become, that in 1762 he was elected professor of anatomy in the institute of his native city, when his lectures, although not remarkable for eloquence, were clear, accurate, and comprehensive, and enjoyed much popularity. His writings are not numerous, but all contain valuable scientific matter, and are characterized by a rare precision and minuteness of details. Two treatises, which added considerably to his reputation, are-Considerations on the Urinary Organs, and On the Organs of Hearing of Birds. But to a purely casual discovery G. owes the wide celebrity attached to his name. Many versions of this circumstance have obtained credence; but the simple fact seems to be, that G.'s wife, a woman of penetrating intellect, happened one day to witness with surprise the convulsive muscular movements produced in a skinned frog by its inanimate body having been accidentally brought into contact with a scalpel which lay on the table, and had become charged by contact with an adjoining electrical machine. She hastened to communicate the interesting phenomenon to her husband, who at once instituted a prolonged series of experiments. See GALVANISM, and ELECTRICITY, ANIMAL. G. died Dec. 4, 1798. Some time previously, he had lost in his wife a cherished companion, and was deprived of all his public emoluments, in consequence of his refusal to take the oaths prescribed by the Cisalpine republic, of which Bologna then formed a part. His writings have been chiefly published in the memoirs of the Bologna institute of sciences, including the most remarkable production of his pen, the treatise entitled De Viribus Electricitatis in Motu Musculari Commentarius.

GALVANIC BATTERY.

chemical action.

An apparatus for generating electricity by means of

Batteries are of an almost infinite variety of forms, but they all operate upon the same principle-namely, that of generating electricity out of the energy with which dissimilar chemicals, between which there is an affinity, combine. The pressure of the electricity so produced is always proportionate to the strength of the chemical affinity, while its quantity is proportionate to the quantity of chemicals consumed. The action may, perhaps, be best studied in the simple zinc-copper element or galvanic pair, as it is sometimes called. When a plate of zinc and a plate of copper are partially immersed in dilute sulphuric acid, no electrical or chemical change is apparent beyond, sometimes, a slight disengagement of hydrogen from the surface of the zinc plate. If, now, the plates are connected by a metal wire, the chemical action sets in. A large quantity of hydrogen is disengaged, but this hydrogen is no longer disengaged at the surface of the zinc, but at the surface of the copper plate. Here, then, we have to deal with something more than mere chemical action, for chemical action would be unable to explain either the quantity of hydrogen disengaged when the metals touch, or the fact that this hydrogen is given off at the surface of the copper plate. At the same time, if the wire is examined, it will be found to possess many remarkable thermal, magnetic, and other properties, some of which will be afterwards described. This is the simplest form of the galvanic battery. It is capable of generating a continuous though weak flow of electricity, and has been used to produce many wonderful results. There have been many theories of the action in the galvanic battery, but they were advanced before the subject was fully understood. The action is now known to be as follows, taking the above battery as an example: The sulphuric acid which exists in combination with hydrogen, having a greater affinity for zinc, releases the hydrogen and attaches the zinc, forming sulphate of zinc, while the hydrogen is set free, and being carried away from the zinc by the action of the current, according to Grotthüss' hypothesis, is deposited on the copper and slides up to the surface of the liquid. The pressure of the current of electricity generated is proportionate to the affinity of the sulphuric acid for the zinc, and it becomes evident that the pressure or power of the electricity produced is the equivalent of the energy with which the acid attacks the zinc. But as the hydrogen, which was at first in combination with the acid, resisted its separation from the acid, this affinity must be deducted from the affinity between the zinc and the acid in order to accurately compute from the known affinities of the chemicals the current which will be obtained.

BATTERY OF ELEMENTS.-When a number of copper and zinc pairs, similar to the one already referred to, are put together, so that the copper plate of one cell is placed in conducting connection with the zinc plate of the next, they constitute a galvanic battery. The term battery is sometimes also applied to a number of cells acting as one combination, in whatever way they may be connected. When the terminal copper and zinc plates are connected, the current runs from each copper to each zinc plate outside the liquids, and from each zinc to each copper plate within the liquids; and when the contact is broken, the zinc pole shows negative, and the copper pole positive electricity. The galvanic battery acts thus in all respects as a compound galvanic pair. If the polar wires be connected with a tangent galvanometer, the deflection of the needle caused by the battery will be exactly the same as that effected by one of the cells, provided the wire be thick and a good conductor; but if the zinc end be connected with the ground, and the electric tension of the insulated copper pole be tested by a condenser and torsion balance, its tension is found to be as many times greater than the tension of the same pole of one

cell examined in the same way, as there are cells in the combination. Thus, if two cells be taken, the tension is doubled; if three, tripled; and so on. The electro-motive force of a battery is therefore proportional to the number of cells, supposing, of course, that they are arranged consecutively. Hence the electricity of a battery is better able to force its way through imperfect conductors than that of the simple pair. When the interpolar communication is formed by a thick, short wire, a single cell produces as powerful an effect on the magnetic needle as a battery; but if it be formed by a bad conductor, such as a long and thin wire, or a liquid, the effect is very different. The current of the pair is then nearly stopped, and its influence on the needle is small, while that of the battery continues to flow comparatively unimpaired. When a battery is put up in series, it is said to have a tension arrangement; when put up so that several of the cells are grouped together, so as to act as one large cell, it is said to be arranged for quantity. Thus, twenty cells are arranged for tension when joined in succession; but they may be disposed so as to act as one large cell twenty times as large, or as ten cells twice as large, or as five cells four times as large, and so on. The disposition or size of the cells is determined according to the circuit which they are to supply.

DIFFERENT FORMS OF THE GÅlvanic BatterY.-Volta's pile, the earliest apparatus for producing electricity at any considerable pressure, from chemical action, by joining a number of elements together to form a battery, as explained above, was arranged as follows: A number of pairs of circular copper and zinc plates soldered together at one edge, and separated by a sheet of waterproof substance, were piled upon each other, the zinc of one pair being placed next the copper of the one beneath, and so on; but separated by a piece of woolen cloth moistened. In consequence of the great number of pairs which could be made in this way, the electric tension obtained from the extremities of Volta's pile was considerable, and led to a number of interesting experiments. It is from this battery that the term pile is applied to the galvanic or voltaic battery. The device is now of little but historical interest.

WOLLASTON'S BATTERY.-The original form of the voltaic pile has a great many inconveniences. It has received a great many improvements, the principal object of which is to facilitate manipulation. The Wollaston battery which has these improvements, consists of a large number of simple cells similar to the one described, the plates of which are all attached to one bar or rack, by which they may be lowered into the jars and supported when required for use. The zinc plates are made of thick rolled metal, usually of large size. The copper plates are of thin sheet, and bent so as to surround the zincs, and increase the surface of action by acting upon both sides of the zinc, contact with the latter being prevented by small pieces of cork. To each copper plate a narrow strip of copper is soldered. This is bent into convenient shape and soldered to the zinc plate of the next couple. In this way the couples are all connected, and each couple is immersed in a glass vessel containing acidulated water.

The various batteries already described, which consist essentially of two metals and one liquid, labor under the objection that the currents produced rapidly diminish in strength. This is principally due to three causes. The first is the decrease in the chemical action, owing to the neutralization of the sulphuric acid by its combination with the zinc. This is a necessary action, for upon it depends the current; it therefore occurs in all batteries, and is without remedy, except by replacement of acid and zinc. The second is due to what is called local action—that is, the production of small closed circuits in the active metal, owing to the impurities it contains. The local currents rapidly wear away the active plate without contributing anything to the continuance of the general current. They are remedied by amalgamating the zinc with mercury, by which chemical action is prevented until the circuit is closed. The third arises from the production of an inverse electro-motive force, which tends to produce a current in a direction contrary to the principal current, and therefore to destroy it either totally or partially. This results from the layer of hydrogen gas upon the surface of the copper plate mentioned in the description of the Volta's pair, the action of gas being to tend to send the current in the opposite direction. This is called polarization.

In the fundamental experiment, when the circuit is closed, zinc sulphate is formed which dissolves in the liquid, and at the same time a layer of hydrogen gas is gradually formed on the surface of the copper plate. This diminishes the activity of the combination in more than one way. In the first place it interferes with the contact between the metal and the liquid, in the second place in proportion as the copper becomes coated with hydrogen, we have virtually a plate of hydrogen instead of a plate of copper opposed to the zinc, and in addition the hydrogen, by reacting on the zinc sulphate which accumulates in the liquid, gradually causes a deposition of zinc on the surface of the copper; hence, instead of having two different metals unequally attacked, the two metals become gradually less different, and consequently the total effect and the current become weaker and weaker.

The polarization of the plate (as this phenomenon is termed) may be destroyed by breaking the circuit and exposing the copper plate to the air; the deposited hydrogen is thus more or less got rid of, and on again closing the circuit the current has nearly its original strength. The same result is obtained when the current of another battery is transmitted through the battery in a direction opposite to that of the first. When platinum electrodes are used to decompose water, a similar phenomenon is produced called polar

ization of the electrodes. Becquerel and Faraday have shown that this polarization of the metals results from the deposits caused by the passage of the current.

CONSTANT CURRENT BATTERIES.-With few exceptions, batteries composed of elements with a single liquid, have almost gone out of use, in consequence of the rapid enfeeblement of the current produced. They have been replaced by batteries with two liquids, which are called constant batteries, because their action continues without material alteration for a considerable period of time. The essential point to be attended to in securing a constant current is to prevent the polarization of the inactive metal, the copper in the cells described; in other words, to hinder any permanent deposition of hydrogen on its surface. This is effected by placing the inactive metal in a liquid upon which the deposited hydrogen can act chemically.

DANIELL'S BATTERY. -This was the first form of the constant battery, and was invented by Daniell in the year 1836. As regards the constancy of its action, it is, perhaps, still the best of all constant batteries. Fig. 1 represents three elements connected to

gether. A glass or porcelain vessel G contains a saturated solution of copper sulphate, in which is immersed a copper cylinder C open at both ends and perforated with holes. At the upper part of this cylinder there is an annular shelf also perforated with small holes, and below the level of the solution; this is intended to support crystals of copper sulphate to replace that decomposed as the electrical action proceeds. Inside the cylinder is a thin porous vessel, PC, of unglazed earthenware. This contains either water or solution of common salt, or dilute sulphuric acid, in which is placed the cylinder of amalgamated zinc Z. Two thin strips of copper fixed by binding screws to the copper and to the zinc serve for connecting the elements in series. When a Daniell's element is closed, the hydrogen resulting from the action of the dilute acid on the zinc is liberated on the surface of the copper plate, but meets there the copper sulphate, which is reduced, forming sulphuric acid and metallic copper, which is deposited on the surface of the copper plate. In this way copper sulphate in solution is taken up, and if it were all consumed hydrogen would be deposited on the copper, and the current would lose its constancy. This is prevented by the crystals of copper sulphate, which keep the solution saturated. The sulphuric acid produced by the decomposition of the sulphate permeates the porous cylinder and tends to replace the acid used up by its action on the zinc, and as the quantity of sulphuric acid formed in the solution of copper sulphate is regular and proportional to the acid used in dissolving the zinc, the action of this acid on the zinc is regular also, and thus a constant current is produced.

In order to join together several of these elements to form a battery, the zinc of one is connected either by a copper wire or strip with the copper of the next, and so on from one element to another, as shown in the figure.

Instead of a porous earthenware vessel a bag of sail cloth may be used for the diaphragm separating the two liquids. The effect is at first more powerful, but the two solutions mix more rapidly, which weakens the current. The object of the diaphragm is to allow the current to pass, but to prevent as much as possible the mixture of the two liquids. The current produced by a Daniell battery is constant for some hours. Its action is stronger when it is placed in hot water.

GROVE'S BATTERY consists of platinum zinc couples. Fig. 2 shows an arrangement of three cells of it. The outer cell of glass is filled with dilute sulphuric acid, one part of acid to eight of water, in which a cylindrical plate of zinc is immersed. Inside the