Volume 18 (1869) (430 pages)

The Mining and Scientific Press. 19 Mechaniteal. Tue Corsish Posmrxo Excixy.—\W. H. G. West, 1st Assistant Engineer, U. 8S. Navy, sends an article te tho Journal af the Feanklin Institute, from which we extract tho fcllowing: “The real causes of tho snecess of the Cornish pumping engine are so simple, that only men of very practical miuds discover and appreciate thein; and this simple maehine remains a mystery even to those who have made its mauuficture their priucipal oscnpation. Tho simplest and cheapest way to pump water, is to foreo some perfectly smooth substance, without appreciable porcs, iuto the body of water, so thatthe water may rise a correspondiag amount and flow away. Here we have no friction, no leaks, and, therefore, no loss of efliciency. All the power is utilized. When wo add a casing or working barrel with packiug, we add friction; when wo add valves, wo add tho work of forcing thom open; when we add reciving and delivery pipes, wo add frictiou; when we add turns, we add obstructions; when we contract the pipes or valves, we add thousands of smaller obstructions, and increase the friction, as the square of the speed of the water through the pipes must increasc; and when the valves aro lifted, they take time to get down again, and water must leak hack. Cornish pumps, well designed, have large pipes. Cornish pumps are packed with soft, elastic hemp packing, or the hest snbstitute at hand, and the cup of thegland is kept full ofsome fluid lubricating matter. The valves or clacks of the Coruish pumps are made of large diameter and small lift; they shut quickly, aud the leak back through them is correspondiugly small. The stroke of the plunger is always long, and tho times of leaking hack are thereby lessened. There is hut one turn in the Cornish pumps—that from the plungereaso to the column.” Tue “ Moss-rvubBer” INKING-ROLLER.— A roller which, according to the Mechanics’ Mugazine is destined to supersede that in ordinary use with printers, is the invention of Stephen Meulton, of Bradford, and is thus prepared: “The inventor takes the ordinary vulcauized india-rubher, and reduces it to powder. He then places it in a inold, and subjects it toa second vulcanizing heat, which converts it into a homogencous mossy sulstance. Itis then covered with a skin of ruhber aud sulphur, aud again subjected to a vulcanizing heat in order to cure the rnbber skin, after which the roller is ready for use. ‘he result of this process is an article composed of ahomogeneous material of the consistency of moss, which is hermetically sealed in a smooth skiu of india-rubher. The advantages possessed hy these rollers are importaut to the printing trade; they are very durahle, on account of the unchangeable character of the material; they are unaffected by temperature; are not damaged by use on hrass rule; are permanently soft aud elastic; seldom require washing, and when washed for changeof color are ready for use immediately.” A Nrvery-Ton Castine 1x Turner Hours. Oue of the large blocks of iron to be employed by the Russian Government for fortification purposes, was recently cast at Krupp’s iron works, at Essen,—says a Berlin letter,—in three hours and forty-five seconds, The fraction is for the actual time occupied in the casting,—the melting havying heen done inthreehours. In Englaud, the casting of a steam hammer, weighing une hundred tons, requires forty-eight hours, These large blocks or plates are moved by a hydraulic crane, aud with perfect ease. They will not be fastened together, with bolts and screws, but will be made to dovetail into each other. They are to be used in connection with earth embankments. A Yanrrn Macuine my Eneuanp.—F. Watkins weut to Euglaud in 1856 to sell his patent machiue for making bolts and nuts. He gave itup after several attempts, and eommenced the manufacture of those artieles ona small scale. In two years he had all he could do. His works have extonded until they now cover twenty-four acres of ground in Birmingham, and employ twenty-five huudred hands. He makesone hundiel tons of holts and nuts per day. Damasecvs Srery.—The Indian damusk is made af Lueknow. All the workinen are Jersiwus, onc of the maimfacturers being known from antiquity. lis name is Mirza Hussein Chirazi, ‘he damask consists of three parts silicate of iron, ono part cast iron, and two parts very puro iron. These substances are pnt in cruciblos which coutain five to forty miskais (25 to 200 grains. ) ;! the latter aro then set in a furnace and kept therein for six days at a strony heat. Such furnaces are made to contain from 10,000 to 12,000 crucibles. Wheu the metal is solidified they are lroken to picces, the iron being brought in an annealing oven and kept therein for forty-eight hours, where it is left tocool slowly. It this precaution is neglected the damask becomes brittle as glass and useless. ‘The damask of Kaswine is mado in the same way, but instoad of common iron the heads of old horseshoe nails are taken, Tho damask of Khorassan is superior to those alroady mentioned. Since the supremacy of NaderCheah, who dostroyed all its ovens, it is no longer manufactured. Tho damask of Arsindgan, Neres, and Schiras, is sold for an equal weight of gold, thero heing very little iu existence, as all the furnaces of thoso placcs huve been dostroyed long ago and uever rehuilt. The damask of Khorassan possesses dark designs and is very hrilliaut. That of Kaswine possesses a goldlike reflex. The designs are intertwisted, presentiug in general a series of circles. The armorers buy the damask, the quality of which they know from long expcricuce. For the purpose of testing it they heat, for instance, a piece to red heat aud forgo it then to a length of one foot anda half. If scintillation takes placo it is considered of a bad quality, and also when the surface does not present a perfect eveuness. CompressED Lrsraer.—The fron Age says that a substance under this name is now made by reducing to a fihrous mass the cuttings of hides aud shoemaker's waste, and mixing them with water containing one per cent. of sulphuric acid, until the whole becomes a plastic mass, which is then pressed into molds of the desired size and shape. After drying hy steam, it is pressed through rolls glazed on oue side and roughened on the other, to produce the grain and flesh sides of the leather. Ahout one pound of glycerine to the hundred weight is added, to render the leather flexible. For many purposes, as for soles and heels of shoes, etc., it is equal to natural leather, and can he sold at one half the cosf. New Euecrric Laure.—The London Mechanics Magazine describes a new lamp, exhihited by Mr. John Browning, F.R.A.S., at a recent meeting of the British Association,—which is to he worked by a Grove’s battery of only six eclls, and is intended for the use of photographers in printing trausparencies. In it, the carbon points instead of being pulled a short distance apart, are allowed to touch each other, and are fastened in that position, so that the current hasto hurn a space between them for itself. A mechanical arrangemeut causes the contact to be renewed as soonas the wasting away of the points breaks the communication. The electric light is destined to supersede both gas light and the lime light for photographie purposes. PRECAUTION IN ARRANGEMENT OF Macuinery.—The American Artisan, in an article deprecating the fool-hardy neglect of the most ordinary safoguards against accidents from machinery in motiou, which one so ofteu sees, mentions the followiug instance which came under the notico of the writer: A naked belt running in a horizontal position was arranged at tho inner side of a stairway so narrow that two persons could not ascend it abreast, yct men passed up and down these steps many times aday, with the certaiuty that if an arm touched the edges of the rapidly-moving belt, veiu and tendou wonld be severcd as by the contact of a band-saw. ‘This, however, was not all; for the outer side of the stairway had uo hand-rail, and should a person loss his balance, in a startled effort to escape if touched by the belt just mentioned, he would be almost certain to fall npou the upper edges of another belt working in vertical planes, andarranged near the outer or open side of the stairway. fifteen foet, Selentific Wiscellanr. Tur Fuorwa Sunte-uears.—Dr. Jeffries Wyman, who has visited the sholl-mounds of East Vlorida, descrihes them iu the American Natwalist as varying in size from circular heaps fifteeu or twenty feet in diametor, and a few inches high, to leug ridges several hundred foot in length, and having a hight from a few inches to four or five feet; in some cases being as high as ‘They are composed almost exclusively of some three species of shells, the Ampullaria depressa, Paludina multinlinca’a, aud Unio Buckleyi, They aro distributed ovor a distanco of moro thau ‘150 miles, They are genorally overgrown with ouks, maples, palmettos, bays, magnolias, etc.; aud in several cases with groves of the wild orango,® tree which was prohahly introduced hy the Spaniards. . Thoy are unquestionahly of human origin. Fragments of pottery, of the bones of various edihle auimals, and iu somo cases charcoal with half-formed shells, were found at different depths, Ornamonts of bone were found in somo of the mounds, and in one a piece of “‘ chipped” flint. The conclusion arrived at, after careful iuspection of dead oak trees Lying upon the tops of some of these mounds, and which must have sprouted, grown, died and fallen, since the completion of the mounds upon which they lie, is that this completion must he referred, as regards its epoch, to a point at least a century before the discovery of the continent, and perhaps much earlier. Wonpgers oF tHe Muioroscorr, —The following is an extract from a lecture upon “‘The Microscope and its Revelations,” delivered on Nov. 25th, before the American Institute, by President Barnard, of Columbia College, New York: ‘Suppose a little drop ef water, such as might be lifted upon the point of a pencil ; within this insignificant space may be easily contained, of some of the smaller organisms, a uumber not less than two thousand millions— that is to say, more than double the number of the human inhabitants of the entire earth. Even this will fail to convey an adequate idea of the extreme minuteness of the objects we are considering ; for such numbers as millions and thousands of millions are totally inconceivable by the mind. The names are mere sounds, which sorve us for symhols in making computations, hut to which it is impossihle to attach auy clear notions. Let us try another illustratiou. Draughtsmen, and persons who have oceasion to make use of divided rules, are aware that a division fiuer than ahout 150 to the inch is with difficulty discerned. Few eyes will distinguish lines closer than 200 to the inch. Divisious so fine as 1,000 to the inch defy the keenest vision to separato them at all. A cube, therefore, having its sides only equal to the one-thousandth part-of inch, is an object invisiblo to the unaided human eye. But such a euhe is large enough to hold not less than 2,000 of the minuter monads.” Metzors anp Sronz SHowrrs.—The remarkable meteor of Oct. 7th, which was seen bothin HEugland and France, is descrihed by the journals of both as illuminating the earth for some seconds with a hluish electrical light so powerful as to completely overpower the moon, which was shining brightly at the time. Le Petit Journal, of Paris, says that in a couversation between one of its contributors and M. Chapelas-Coulvier-Gravier, a celebrated French observer, the latter gave it as his opinion that meteors and the showers ot stones which have so frequently been said to accompany or to follow them, are, contrary to the generally received belief, entirely distinct phonomena. Puatinum iv Vinegar Marine.—Artus, iu his Vierteljjahresschrifi, recommends to dissolve oue-half ounce of dry bichloride of platinum in five ponnds alcohol, saturate therewith throe pouuds of wood charcoal, broken to the size of a hazel-nut, and iguite in a covored crucible; and to use tho product in the well-known way in the oxidation of alcohol to acetic acid. He states its action to be surprisingly rapid and complete, and that the vinegar obtaiued has a ploasant flavor and odor. This seems an improvement of snfliciont practical promise to be worthy of record.—Prof. Wauriz, Sanur anp Raprican.—Thos, Wood, F. . S., writes tho Chemical News, suggesting new definitions for these words. At present the term salt is very vaguely used, and not oasily uuderstood by learners, Chemists, even. aro nnable to state clearly, briefly and concisely what they mcan hy the word: Mr. Wood defines a radical to ho any body that, without itself suffering decemposition is capable of entering into vhemieal comhination with another. Further, radicals are either simplo or compouud, real or imaginary. Simplo radicals are tho elements; compound radicals are such bodies as Cy, ete.; and imaginary radicals, as SO', NO}, ete., aro tloso which have never heeu isolated, and, like atoms, only exist iu the mind aud innagiuation of the chemist, created for his own use and convenience, hut rondering the acquirement of the scieuco hy the young much moro difficult than it would he without them. If these views of a radical he correct, a salt. willhe auy compound formed hy the union of twoor more radicals, and will take its characteristic place and name from the radicals composing it. From this definition it would result that a compouud radical is already a salt. If, howover, a componnd be capable of uniting with another, or taking part in a chemical equation withoutitself suffering decomposition, it should receive the uame radical, compound radical, or salt radical, to distinguishit from a true salt. Thus HCl, HNO’, and H?, SO!, are trne salts composed each of more than one radieal, If these bodies are salts with a sour taste, let us teach that they are such, and not that they are a special class of chemical compounds capable of gencratiug salts; for radicals, not acids and bases, are the bodics of which salts are composed. Eanruquakes.—At a recent meeting ef the Polytechnic Branch of the American Iustitute, in New York, Dr. J. J. Edwards read a paper upon this subject, which is thus reported: He argued that the earth is kept in its parts by the reciprocation of attraction and repulsion; that the earth is not a molten mass in its interior, although it may once have beeu; that the heat of the earth is uot sufficient to account for earthquakes, nor for the phenomena which are necessary for the vegetahle and animal life on its surface; that the laws which govern the sun and the planets are universal laws, and that to know tho laws ofone is toknow approximately the laws of the whole, and that the differences are ouly of degree and variety, and not fundameutal; that a meteor or aérolito is a planet, and, consequently, its component parts indicate the structure of the earth; that the sun is the fountaiu of our motion and life; that heat, light and electricity are solar emanations, directly or indirectly; that the new scientific laws of the corelations of forees and the conservation of forces are the key to the cause of earthquakes; that the earth stores up any superabundance of heat or light in their eorelation to electricity, and that earthquakes are caused by the diseharge of this superabundant electricity in its endeavors to equalize itself over the earth or to discharge itself into the surrounding atmosphere under the same laws as the Leyden jar. The lecturer concluded by stating that inasmuch as the greator part of the paper was composed of quotations from others he was not responsible for them, thongh he heartily conenrred in them, belicving electricity to be the cause of earthquakes. “ Ganvanio Action or Corpar-Borromep Sares iv Dock.—Some month since, the “Elk,” a new English screw gunboat, was placed in the old shipping-hasin at Portsmouth dockyard, where sho lay ten weeks waiting for her screws. When these were ready, it was fonnd that galvanic action had actually reduced the key pieces on the shaftiugs to plumhago, and had honcycombed other parts of the thatal. ‘T]he Chemical News says that ‘‘the fact appears to be that the small area of water in the old ship-basin is but seldom opened to the admission of the tide, has always three or four copper-bottomed vessels floating upon it, and is therefore a chemical bath.”

The Mining and Scientific Press. 19 Mechaniteal. Tue Corsish Posmrxo Excixy.—\W. H. G. West, 1st Assistant Engineer, U. 8S. Navy, sends an article te tho Journal af the Feanklin Institute, from which we extract tho fcllowing: “The real causes of tho snecess of the Cornish pumping engine are so simple, that only men of very practical miuds discover and appreciate thein; and this simple maehine remains a mystery even to those who have made its mauuficture their priucipal oscnpation. Tho simplest and cheapest way to pump water, is to foreo some perfectly smooth substance, without appreciable porcs, iuto the body of water, so thatthe water may rise a correspondiag amount and flow away. Here we have no friction, no leaks, and, therefore, no loss of efliciency. All the power is utilized. When wo add a casing or working barrel with packiug, we add friction; when wo add valves, wo add tho work of forcing thom open; when we add reciving and delivery pipes, wo add frictiou; when we add turns, we add obstructions; when we contract the pipes or valves, we add thousands of smaller obstructions, and increase the friction, as the square of the speed of the water through the pipes must increasc; and when the valves aro lifted, they take time to get down again, and water must leak hack. Cornish pumps, well designed, have large pipes. Cornish pumps are packed with soft, elastic hemp packing, or the hest snbstitute at hand, and the cup of thegland is kept full ofsome fluid lubricating matter. The valves or clacks of the Coruish pumps are made of large diameter and small lift; they shut quickly, aud the leak back through them is correspondiugly small. The stroke of the plunger is always long, and tho times of leaking hack are thereby lessened. There is hut one turn in the Cornish pumps—that from the plungereaso to the column.” Tue “ Moss-rvubBer” INKING-ROLLER.— A roller which, according to the Mechanics’ Mugazine is destined to supersede that in ordinary use with printers, is the invention of Stephen Meulton, of Bradford, and is thus prepared: “The inventor takes the ordinary vulcauized india-rubher, and reduces it to powder. He then places it in a inold, and subjects it toa second vulcanizing heat, which converts it into a homogencous mossy sulstance. Itis then covered with a skin of ruhber aud sulphur, aud again subjected to a vulcanizing heat in order to cure the rnbber skin, after which the roller is ready for use. ‘he result of this process is an article composed of ahomogeneous material of the consistency of moss, which is hermetically sealed in a smooth skiu of india-rubher. The advantages possessed hy these rollers are importaut to the printing trade; they are very durahle, on account of the unchangeable character of the material; they are unaffected by temperature; are not damaged by use on hrass rule; are permanently soft aud elastic; seldom require washing, and when washed for changeof color are ready for use immediately.” A Nrvery-Ton Castine 1x Turner Hours. Oue of the large blocks of iron to be employed by the Russian Government for fortification purposes, was recently cast at Krupp’s iron works, at Essen,—says a Berlin letter,—in three hours and forty-five seconds, The fraction is for the actual time occupied in the casting,—the melting havying heen done inthreehours. In Englaud, the casting of a steam hammer, weighing une hundred tons, requires forty-eight hours, These large blocks or plates are moved by a hydraulic crane, aud with perfect ease. They will not be fastened together, with bolts and screws, but will be made to dovetail into each other. They are to be used in connection with earth embankments. A Yanrrn Macuine my Eneuanp.—F. Watkins weut to Euglaud in 1856 to sell his patent machiue for making bolts and nuts. He gave itup after several attempts, and eommenced the manufacture of those artieles ona small scale. In two years he had all he could do. His works have extonded until they now cover twenty-four acres of ground in Birmingham, and employ twenty-five huudred hands. He makesone hundiel tons of holts and nuts per day. Damasecvs Srery.—The Indian damusk is made af Lueknow. All the workinen are Jersiwus, onc of the maimfacturers being known from antiquity. lis name is Mirza Hussein Chirazi, ‘he damask consists of three parts silicate of iron, ono part cast iron, and two parts very puro iron. These substances are pnt in cruciblos which coutain five to forty miskais (25 to 200 grains. ) ;! the latter aro then set in a furnace and kept therein for six days at a strony heat. Such furnaces are made to contain from 10,000 to 12,000 crucibles. Wheu the metal is solidified they are lroken to picces, the iron being brought in an annealing oven and kept therein for forty-eight hours, where it is left tocool slowly. It this precaution is neglected the damask becomes brittle as glass and useless. ‘The damask of Kaswine is mado in the same way, but instoad of common iron the heads of old horseshoe nails are taken, Tho damask of Khorassan is superior to those alroady mentioned. Since the supremacy of NaderCheah, who dostroyed all its ovens, it is no longer manufactured. Tho damask of Arsindgan, Neres, and Schiras, is sold for an equal weight of gold, thero heing very little iu existence, as all the furnaces of thoso placcs huve been dostroyed long ago and uever rehuilt. The damask of Khorassan possesses dark designs and is very hrilliaut. That of Kaswine possesses a goldlike reflex. The designs are intertwisted, presentiug in general a series of circles. The armorers buy the damask, the quality of which they know from long expcricuce. For the purpose of testing it they heat, for instance, a piece to red heat aud forgo it then to a length of one foot anda half. If scintillation takes placo it is considered of a bad quality, and also when the surface does not present a perfect eveuness. CompressED Lrsraer.—The fron Age says that a substance under this name is now made by reducing to a fihrous mass the cuttings of hides aud shoemaker's waste, and mixing them with water containing one per cent. of sulphuric acid, until the whole becomes a plastic mass, which is then pressed into molds of the desired size and shape. After drying hy steam, it is pressed through rolls glazed on oue side and roughened on the other, to produce the grain and flesh sides of the leather. Ahout one pound of glycerine to the hundred weight is added, to render the leather flexible. For many purposes, as for soles and heels of shoes, etc., it is equal to natural leather, and can he sold at one half the cosf. New Euecrric Laure.—The London Mechanics Magazine describes a new lamp, exhihited by Mr. John Browning, F.R.A.S., at a recent meeting of the British Association,—which is to he worked by a Grove’s battery of only six eclls, and is intended for the use of photographers in printing trausparencies. In it, the carbon points instead of being pulled a short distance apart, are allowed to touch each other, and are fastened in that position, so that the current hasto hurn a space between them for itself. A mechanical arrangemeut causes the contact to be renewed as soonas the wasting away of the points breaks the communication. The electric light is destined to supersede both gas light and the lime light for photographie purposes. PRECAUTION IN ARRANGEMENT OF Macuinery.—The American Artisan, in an article deprecating the fool-hardy neglect of the most ordinary safoguards against accidents from machinery in motiou, which one so ofteu sees, mentions the followiug instance which came under the notico of the writer: A naked belt running in a horizontal position was arranged at tho inner side of a stairway so narrow that two persons could not ascend it abreast, yct men passed up and down these steps many times aday, with the certaiuty that if an arm touched the edges of the rapidly-moving belt, veiu and tendou wonld be severcd as by the contact of a band-saw. ‘This, however, was not all; for the outer side of the stairway had uo hand-rail, and should a person loss his balance, in a startled effort to escape if touched by the belt just mentioned, he

would be almost certain to fall npou the upper edges of another belt working in vertical planes, andarranged near the outer or open side of the stairway. fifteen foet, Selentific Wiscellanr. Tur Fuorwa Sunte-uears.—Dr. Jeffries Wyman, who has visited the sholl-mounds of East Vlorida, descrihes them iu the American Natwalist as varying in size from circular heaps fifteeu or twenty feet in diametor, and a few inches high, to leug ridges several hundred foot in length, and having a hight from a few inches to four or five feet; in some cases being as high as ‘They are composed almost exclusively of some three species of shells, the Ampullaria depressa, Paludina multinlinca’a, aud Unio Buckleyi, They aro distributed ovor a distanco of moro thau ‘150 miles, They are genorally overgrown with ouks, maples, palmettos, bays, magnolias, etc.; aud in several cases with groves of the wild orango,® tree which was prohahly introduced hy the Spaniards. . Thoy are unquestionahly of human origin. Fragments of pottery, of the bones of various edihle auimals, and iu somo cases charcoal with half-formed shells, were found at different depths, Ornamonts of bone were found in somo of the mounds, and in one a piece of “‘ chipped” flint. The conclusion arrived at, after careful iuspection of dead oak trees Lying upon the tops of some of these mounds, and which must have sprouted, grown, died and fallen, since the completion of the mounds upon which they lie, is that this completion must he referred, as regards its epoch, to a point at least a century before the discovery of the continent, and perhaps much earlier. Wonpgers oF tHe Muioroscorr, —The following is an extract from a lecture upon “‘The Microscope and its Revelations,” delivered on Nov. 25th, before the American Institute, by President Barnard, of Columbia College, New York: ‘Suppose a little drop ef water, such as might be lifted upon the point of a pencil ; within this insignificant space may be easily contained, of some of the smaller organisms, a uumber not less than two thousand millions— that is to say, more than double the number of the human inhabitants of the entire earth. Even this will fail to convey an adequate idea of the extreme minuteness of the objects we are considering ; for such numbers as millions and thousands of millions are totally inconceivable by the mind. The names are mere sounds, which sorve us for symhols in making computations, hut to which it is impossihle to attach auy clear notions. Let us try another illustratiou. Draughtsmen, and persons who have oceasion to make use of divided rules, are aware that a division fiuer than ahout 150 to the inch is with difficulty discerned. Few eyes will distinguish lines closer than 200 to the inch. Divisious so fine as 1,000 to the inch defy the keenest vision to separato them at all. A cube, therefore, having its sides only equal to the one-thousandth part-of inch, is an object invisiblo to the unaided human eye. But such a euhe is large enough to hold not less than 2,000 of the minuter monads.” Metzors anp Sronz SHowrrs.—The remarkable meteor of Oct. 7th, which was seen bothin HEugland and France, is descrihed by the journals of both as illuminating the earth for some seconds with a hluish electrical light so powerful as to completely overpower the moon, which was shining brightly at the time. Le Petit Journal, of Paris, says that in a couversation between one of its contributors and M. Chapelas-Coulvier-Gravier, a celebrated French observer, the latter gave it as his opinion that meteors and the showers ot stones which have so frequently been said to accompany or to follow them, are, contrary to the generally received belief, entirely distinct phonomena. Puatinum iv Vinegar Marine.—Artus, iu his Vierteljjahresschrifi, recommends to dissolve oue-half ounce of dry bichloride of platinum in five ponnds alcohol, saturate therewith throe pouuds of wood charcoal, broken to the size of a hazel-nut, and iguite in a covored crucible; and to use tho product in the well-known way in the oxidation of alcohol to acetic acid. He states its action to be surprisingly rapid and complete, and that the vinegar obtaiued has a ploasant flavor and odor. This seems an improvement of snfliciont practical promise to be worthy of record.—Prof. Wauriz, Sanur anp Raprican.—Thos, Wood, F. . S., writes tho Chemical News, suggesting new definitions for these words. At present the term salt is very vaguely used, and not oasily uuderstood by learners, Chemists, even. aro nnable to state clearly, briefly and concisely what they mcan hy the word: Mr. Wood defines a radical to ho any body that, without itself suffering decemposition is capable of entering into vhemieal comhination with another. Further, radicals are either simplo or compouud, real or imaginary. Simplo radicals are tho elements; compound radicals are such bodies as Cy, ete.; and imaginary radicals, as SO', NO}, ete., aro tloso which have never heeu isolated, and, like atoms, only exist iu the mind aud innagiuation of the chemist, created for his own use and convenience, hut rondering the acquirement of the scieuco hy the young much moro difficult than it would he without them. If these views of a radical he correct, a salt. willhe auy compound formed hy the union of twoor more radicals, and will take its characteristic place and name from the radicals composing it. From this definition it would result that a compouud radical is already a salt. If, howover, a componnd be capable of uniting with another, or taking part in a chemical equation withoutitself suffering decomposition, it should receive the uame radical, compound radical, or salt radical, to distinguishit from a true salt. Thus HCl, HNO’, and H?, SO!, are trne salts composed each of more than one radieal, If these bodies are salts with a sour taste, let us teach that they are such, and not that they are a special class of chemical compounds capable of gencratiug salts; for radicals, not acids and bases, are the bodics of which salts are composed. Eanruquakes.—At a recent meeting ef the Polytechnic Branch of the American Iustitute, in New York, Dr. J. J. Edwards read a paper upon this subject, which is thus reported: He argued that the earth is kept in its parts by the reciprocation of attraction and repulsion; that the earth is not a molten mass in its interior, although it may once have beeu; that the heat of the earth is uot sufficient to account for earthquakes, nor for the phenomena which are necessary for the vegetahle and animal life on its surface; that the laws which govern the sun and the planets are universal laws, and that to know tho laws ofone is toknow approximately the laws of the whole, and that the differences are ouly of degree and variety, and not fundameutal; that a meteor or aérolito is a planet, and, consequently, its component parts indicate the structure of the earth; that the sun is the fountaiu of our motion and life; that heat, light and electricity are solar emanations, directly or indirectly; that the new scientific laws of the corelations of forees and the conservation of forces are the key to the cause of earthquakes; that the earth stores up any superabundance of heat or light in their eorelation to electricity, and that earthquakes are caused by the diseharge of this superabundant electricity in its endeavors to equalize itself over the earth or to discharge itself into the surrounding atmosphere under the same laws as the Leyden jar. The lecturer concluded by stating that inasmuch as the greator part of the paper was composed of quotations from others he was not responsible for them, thongh he heartily conenrred in them, belicving electricity to be the cause of earthquakes. “ Ganvanio Action or Corpar-Borromep Sares iv Dock.—Some month since, the “Elk,” a new English screw gunboat, was placed in the old shipping-hasin at Portsmouth dockyard, where sho lay ten weeks waiting for her screws. When these were ready, it was fonnd that galvanic action had actually reduced the key pieces on the shaftiugs to plumhago, and had honcycombed other parts of the thatal. ‘T]he Chemical News says that ‘‘the fact appears to be that the small area of water in the old ship-basin is but seldom opened to the admission of the tide, has always three or four copper-bottomed vessels floating upon it, and is therefore a chemical bath.”