Volume 24 (1872) (424 pages)

January 13, 1872.) SCIENTIFIC PRESS. 19 Mechanica ‘ProcRess , The Durability of Timber.A late edition of Vredgold on carpentry furuishes the followiug interesting and useful facts with regard to the durability of ditlerent kinds of timber: In regard tothe durability of different woods, the most odoriferons kinds are generally cousidered to be the most durable; also wouds of a close aud compact texture are gouerally more durable than those that are open and porous, but there aro excoptions, as the wood of the evergreen vali, is more compact than that of the common oak, but not noarly so durable. Sir Il, Davy has observed that, “in general, tho quantity of eharcoal atlorded by woods offers a tolerable accurate indicatiou of their durability; thoso most abundant in charcoal and oarthy matter are most permanent; and those that contain the largest proportion of gaseous clements are the most destructiblo, ‘Amongst our own trees,” ho adda, ‘the chestnut and the oak are pro-ominent as to durability, aud tho ehestunt affords rather more carbonaccous matter than the oak. Bunt we know from experience, that red or yellow fir is as durable as tho oak in most situations, though it produces less charcoal by the ordinary process, ‘The following tablo of the qnantity of charcoal afforded hy 100 parts of different woods is added, for the informatiou of the reader: oe OR nOumerercetee. sae es Scoteh Pine. . LON 2) Ola janoo Oem cendod Chestuut . Mahogany. Wainy Satlow,, Birch.. . 15.6 , Syeamor But it does uot appear that-tho proportion of charcoal is a satisfactory criterion of the durahility. An experiment to detormino tho compatative dnrability of different woods is related in Young's ‘‘Annals of Agriculture,” which will be moro satisfuetory than any specnlative opinion; and it is much to be regretted that such experiments have not been oftencr made. “Inch and half planks of trees from thirty to forty-five years’ growth, after ten years’ standing in the weather, were examamined and found to be in the following state and condition: Cedar, perfectly sonnd; larch, the heart sound, but sap qnite decayed; spruee fir, sound; silver fir, in decay; Scotch fir, mnch decayed; pinaster, chestnut, perfectly souud; abele, sound; walnut, in decay; syeamoro, much deeayed; boech, sonud; birch, quite rotten. This shows at once the kinds that are best adapted to resist the weather; but even in the sumo kind of wood there is much differeuce inthe durability, and the ohservation is as old as Pliny, that ‘‘the timber of those trees which grow in moist and shady places is notso good as that which comes frem a more exposed situation, nor is it so close, substantial, and durable;” and Vitruvins has made similar observations. Also split timher is more durahle than sawed timber, for the fissure in splitting follows the grain, and leaves it whole, whereas the saw divides tho fibers and moisture finds more ready access to the internal parts of the wood. Split timber is also strouger thau sawed timber because the fibers, being continnous, resist hy means of their lougitndinal strength; but when dividedby tiie saw, the resistanco often depends on the lateral cohesion of the fibers, which is in some woods only one twentieth of the direct cohesion of the same fihers. For the same reason whole treos are stronger than specimens, unloss the specimens be selected of a straight grain, bnt the difference in large scantling is so small as not to be deserving of notice in practice. Of the durability of timber in a wet state, the piles of the bridge, built by the Emperor Trajan across the Danube, ave an example. One of these piles was taken up, and found to be petrified to the depth of three fourths of on inch; but the rest of the wood was little differeut from its ordinary state, thongh it had beeu driven more than sixteen centuries. The piles under the piers of old London Bridge had been driven about 600 years, and, from Mr. Dauce’s observatious in 1746, it did net appear that they were materially decayed; indeed they were found to the last to be suiliciently sound to support the massy superstructure. They were chiefly of elm. Also, in digging away the foundation of old Savoy Palace, Loudon, built nearly 700 years ago, the whole of the piles, conquite rotteu;. sisting of onk, elm, heech, and chestunt, wore fouud iu n state of perfect soundness; as also was the planking which coyered the pile heads. On opening one of the tombs at Thebes, M. Belzeni discovered two statues of wood, in good preservation; the only docayed parts being the sockets to receive the eyes. The wood of these statnes is probably the oldest in existeuco that hears the traces of human labor. Mechanical Progress in the United States. Thoro is nothing whieh brings the inaterial progross of the United States into more prominent light than a retrospectivo view of the condition of affairs forty years ago, in regard to the capacities of our mechanics to produce niachinery. In 1828, the first locomotive was imported from lingland, to draw the eoal-cars on the Carbondale and Ionesdalo Railroad, Pa.; tho second in 1830, to run passenger-cars on tho Mohawk and Hudson Railroad. The first American locomotive was built in 1830, in the United States Foundry, at West Point, for the South Carolina Railroad, and tho third in 1831, for the Mohawk aud Hudsou Railroad, which road was soon abandoned aud hroken up for want of patronage. In the sauic year Baldwin, of Philadelphia, ninde a miniature locomotivo, which conld draw two little cars with four persons; he exhibited it in Peale’s Musenm, iu Philadelphia, and this exhibition laid the foundation for his fortune, aud the largo machine shop in that city, still hearing his name. In the following year, he roceived au order from the Germantown Railroad Company to build a large Iocomotive. It would have frighteued any other man of less pluck, as in the wholo city thore were only five men who were ahle to help him, and no proper tools at all, Ile therefore commenced at once to make tools aud patterns, and, incredible as it seems, in six months the locomotive was rendy. It appears to have been a very delicate affair, as the advertisements in the Philadelphia papers of that day prove. They say, ‘‘Passengers to Germantown will go with a train of cars drawn hy the new engiue, when the weather is fair; when it raius, the horses will draw the cars.” Notwithstanding this, Baldwin’s reputation was settled; before the end of 1834, he had finished five locomotives. He was then able to fiuish two small ones in a year; now the same shop finishes one of large size, with tender, etce., every day. The first small locomotives could run with a velocity of ten miles an hour, and draw ene or two tons; the present locomotives have a speed of 40 miles per hour, and draw 1,000 tons. . A business commenced in 1831, with five men, without proper tools, in a smzll shop, (which still stands,) has increased in 1871 to a large manufaetory grown around it, occnpying a quarter of a million sqnare feet, employimg 2,000 men, and mauufacturing four milliou dollars worth oflocomotives per year, which are sent to California, Canada, South America, Europe, etc., in spite of Enropean competition, of cheap labor, and cheap material.— Manufacturer and Builder. Experiments with Lubricators, A very elaborate sories of experiments were recently mado in New York to test the relative value of different lubricators. The experiments were continued during a period offourteen months. The following were the general results and inferences: The consumption of oil varies with its temperature when applied. 7 Winter sperm oil, sustained the heaviest pressure, and was taken as the initial of comparison for all others, and their per eent. of Inbricating value determined by it. ‘The tests of mineral oils and mixtures of animal and fish oils with them wonld uot snstain an equal pressure with the sporm, when eqnal quantities of the oil were applied, without rapidly increasing the tomperatnre of the journals, and producing an abrasion of their surfaces. When the pressure on the boarings were made equal with winter sperm, it required from 100 to 400 per cent. increase of oil, to keep the temperature of the journals below 100° Fahr, Experiments were made at varied velocites, with the same oils. The results proved that as the volocity was reduced the pressnre could be increased, and the relative consumption of oil, applied at equal temperatures, was decreased in almost equal ratio, §clENTIFIC Progress. Meteorites—Their Orbits, Ete. Mnch attention has of late years heen given to that erratio class of heavenly hodies known as meteors, or,,as they are sonletimes called, shooting stars. In raro instances theso hodies reaoli the earth, and when they do, they are usnally called aorolites, or motooric. stoues, from the character of their composition, Thoso which reach tho earth are not snpposed to he in any way ditferent from those which merely blaze out for an iustant, or shoot across a portion of the heavens, leavinff a hright train of light hehind,. When they fall to the earth, their direction is snch as to lead to an unavoidahle collision; those which hecome visible, for a moment only, and do not fall, enter into and pass through the upper and more rarifiod portions of the atmosphere, If their direction is such that they enter deeply into tho atmosphere, hnt not pointed directly to the earth’s surface, their motion isso much retarded by the friction of the air, that their direction is sufficiently changed by gravitation to bring them to the earth, and thus ond their existence as separate and distinct bodies in space. Meteors are of all sizes, from those of a few grains in weight to those of many pounds or even tons. The former, on entering deeply into the atmosphere, are rapidly dissipated by the great heat which is created by their friction, and the consnming effect of the oxygen with which they come in contact. The larger ones are usually fraetnred hy the groat heat produced upon their surface, aud fall in fragments to the carth. Their fracture is usually attended by coneussion, which often sounds like the report of distant canton. The continued, subdued roaring which is often heard during their flight across the heavens in their approach to’the earth, is produced by the rushing past them, laterally, of the air, which falls rapidly in hehind them, to fill the partial vacuum caused by their motion. It has been calenlated that not less than an average of seven millious of meteors might he seen from all parts of the earth, every twenty-four hours, provided the earth shonld move dnring that time through a elear sky, withont any light from the snn or moon. If all the meteors which so pass the earth within the time specitied could be brought into the field of a telescope, it is calenlated, on reliable authority, that the number would reach fully fonr hundred millions! All these hodies move around the sun, and late observations have established the fact that many, if not most of them, move in approximately concentrated orbits, like the asteroids; but unlike the asteroids, in extremely elliptical orbits, like comets, The path of the ‘‘ November meteors” has its aphelion just beyond the orbit of Uranus, and its perhelion at or near the earth’s orbit, and inclined about 17 degrees to that of the earth. Careful observations have lcd to the snpposition that there are at least fifty different rings of meteors, such as the November ring, of which, however, that is by far the most extensive. Chemical analysis has revealed the presence of at least twenty-three different elements in these meteors, ont of the whole number of sixty five thus far discovered as composing the earth’s substance. The names of these elemeutsare asfollows: Oxygen, hydrogen, nitrogen, sulphur, phosphorus, carbon, silicon, nickel, chromium, tin, aluminum, magnesinm, calcium,’ potassium, sodium, eobalt, manganese, iron, copper, titanium, lead, lithium and strontium. The prosence of these elements, found also in the earth, suggests a common origin. The asteroids probably compose a“ ring” very similar to the November meteors; but its great distance from the earth will not admit of any except its larger component parts being scen, even by the telescope. No doubt a closer view would reveal an almost illimitable number, even down to bodies not greater than the larger asteroids. These bodies are supposed to be either the fragments of an exploded planet, or a planetary body thrown off from the sun in the form of aring, and aggregated into a great number of small bodies, instead of into one large body, like the earth and other planets. — , From the eecentrity of the orbits of the meteorites, wemight perhaps suppose them to he fragmentary portions of a cometary body, widely scuttered in space, instead of beiug eoucentrated into a single body, as are the hodies kuowu as coniets, The spectrum, that wonderful instrument of eomparatively reeent discovery, which is jnst beginning to be employed in the observation of comets, appears to indicate that these erratic bedigs ure composed of gases at a very clovated tempcratnre. A cureful microscopie study of mauy of the asteroids which have fallen to the earth, shows most conclusively that these bodies have at some titue heen in a state of vapor —as tho comets now arc—and that proximately they are nade np of smull rounded globnies, which have accumulated and been more or less fractured hy mutual impact, and finally consolidated, ‘I'bese snpposed facts would seem to indieato a eommon origin for comets and meteors. Action or SuLpaurous Acip on PxHosrHates.—B. W. Gerland has heen making some important experiments on the action of aqueons sniphnrous acid upon phosphates, which havo developed some points of great practical importance, especially in their bearing on tho manufacture of artificial composts and solnble phosphates. He finds that aqueons sulphurous acid does not, like the strong acids, wholly decompose the phosphates, but transforms them into soluble modificutions, The ordinary bone phosphate, called tribasic, is easily soluhle in sulphurous acid, and if the solution he hastily boiled and evaporated in open vessels, a crystalline duuble salt, 2 wixtnre of trihasie phosphate with a sulphate of lime, will separate. This new aed remarkahlo body is said to be quite permanent, and in reference to its nse as a disinfectant, aud upou farm land it is certainly deserving of special notice. If we can by means of sulphurous acid decompose the phosphates, we shall avoid the expense of sulphurio acid, which must first he made from snlphurons acid, and obtain a product not so difficult to handle, and capable of a greater variety of uses than the superphosphates made in the eld way. Mr. G. has studied the behavior of sulphurons acid towards other phosphates, the resnIts of which, however, being purely theoretical we omit them. Brome or Porassrum.—The increasing use of bromide of potassium, another of chemistry’s contributions, would have been impossihle, were it not for the extraordinary diseovery of an apparently evaporated sea water hed iu Germany. The amount of bromide consnméd in medicine is dow enormons, aud most of it is derived from this source. The same mines have also completely changed our sonrces of potash; they produce far more than all the other sources of England and France pnt together, and have so reduced the price tbat carbonate of potash is now largely made in England at a price which competes most favorably with American pearlash, and will ultimately drive it out of that market. Bromide of potassium isan iystance of a snbstance long used in meilicine before its valnahle properties werd discovered. Inganation or Dust ny Worxmen.— The injurious effect of exposure to the dust of varions manufacturing establishments has not unfrequently been dwelt upon with more or less force; but we are hardly prepared for the resnlt of certain specific investigations on this subject, It has long been a dispnted point whether the particles of iron, silica, etc., mercly lodge within the air-cells of the Inngs, or penetrate through their walls into the tissue between them. But Professor Zenker informs us that, on examining the Inngs of a woman who had been exposed to the dust of iron oxide, used in preparing books of gold-leaf, he fonnd the powder in the tissne between the air-cells and in their walls, as well as in their cavities. From less than two ounces of this lung over twelve grains of iron oxide were obtained by chemical mothods; so that, if equally distributed through both lungs, there must have heon at least three-quarters of an ounce inhaled. In another case—that of a workman exposed to the dust of a mixture used in preparing ultramarine substances—he found a quantity estimated at fully an ounce.—AHarper's Magazine. M. Deverciz, a French chemist, finds that water containing only one fonr thousandth of its weight of carbolic acid sufficed for the disinfection of the Morgue in Paris during the hottest weather, when it contained six or seven bodies,

January 13, 1872.) SCIENTIFIC PRESS. 19 Mechanica ‘ProcRess , The Durability of Timber.A late edition of Vredgold on carpentry furuishes the followiug interesting and useful facts with regard to the durability of ditlerent kinds of timber: In regard tothe durability of different woods, the most odoriferons kinds are generally cousidered to be the most durable; also wouds of a close aud compact texture are gouerally more durable than those that are open and porous, but there aro excoptions, as the wood of the evergreen vali, is more compact than that of the common oak, but not noarly so durable. Sir Il, Davy has observed that, “in general, tho quantity of eharcoal atlorded by woods offers a tolerable accurate indicatiou of their durability; thoso most abundant in charcoal and oarthy matter are most permanent; and those that contain the largest proportion of gaseous clements are the most destructiblo, ‘Amongst our own trees,” ho adda, ‘the chestnut and the oak are pro-ominent as to durability, aud tho ehestunt affords rather more carbonaccous matter than the oak. Bunt we know from experience, that red or yellow fir is as durable as tho oak in most situations, though it produces less charcoal by the ordinary process, ‘The following tablo of the qnantity of charcoal afforded hy 100 parts of different woods is added, for the informatiou of the reader: oe OR nOumerercetee. sae es Scoteh Pine. . LON 2) Ola janoo Oem cendod Chestuut .. Mahogany. Wainy Satlow,, Birch... .. 15.6 , Syeamor But it does uot appear that-tho proportion of charcoal is a satisfactory criterion of the durahility. An experiment to detormino tho compatative dnrability of different woods is related in Young's ‘‘Annals of Agriculture,” which will be moro satisfuetory than any specnlative opinion; and it is much to be regretted that such experiments have not been oftencr made. “Inch and half planks of trees from thirty to forty-five years’ growth, after ten years’ standing in the weather, were examamined and found to be in the following state and condition: Cedar, perfectly sonnd; larch, the heart sound, but sap qnite decayed; spruee fir, sound; silver fir, in decay; Scotch fir, mnch decayed; pinaster, chestnut, perfectly souud; abele, sound; walnut, in decay; syeamoro, much deeayed; boech, sonud; birch, quite rotten. This shows at once the kinds that are best adapted to resist the weather; but even in the sumo kind of wood there is much differeuce inthe durability, and the ohservation is as old as Pliny, that ‘‘the timber of those trees which grow in moist and shady places is notso good as that which comes frem a more exposed situation, nor is it so close, substantial, and durable;” and Vitruvins has made similar observations. Also split timher is more durahle than sawed timber, for the fissure in splitting follows the grain, and leaves it whole, whereas the saw divides tho fibers and moisture finds more ready access to the internal parts of the wood. Split timber is also strouger thau sawed timber because the fibers, being continnous, resist hy means of their lougitndinal strength; but when dividedby tiie saw, the resistanco often depends on the lateral cohesion of the fibers, which is in some woods only one twentieth of the direct cohesion of the same fihers. For the same reason whole treos are stronger than specimens, unloss the specimens be selected of a straight grain, bnt the difference in large scantling is so small as not to be deserving of notice in practice. Of the durability of timber in a wet state, the piles of the bridge, built by the Emperor Trajan across the Danube, ave an example. One of these piles was taken up, and found to be petrified to the depth of three fourths of on inch; but the rest of the wood was little differeut from its ordinary state, thongh it had beeu driven more than sixteen centuries. The piles under the piers of old London Bridge had been driven about 600 years, and, from Mr. Dauce’s observatious in 1746, it did net appear that they were materially decayed; indeed they were found to the last to be suiliciently sound to support the massy superstructure. They were chiefly of elm. Also, in digging away the foundation of old Savoy Palace, Loudon, built nearly 700 years ago, the whole of the piles, conquite rotteu;. sisting of onk, elm, heech, and chestunt, wore fouud iu n state of perfect soundness; as also was the planking which coyered the pile heads. On opening one of the tombs at Thebes, M. Belzeni discovered two statues of wood, in good preservation; the only docayed parts being the sockets to receive the eyes. The wood of these statnes is probably the oldest in existeuco that hears the traces of human labor. Mechanical Progress in the United States. Thoro is nothing whieh brings the inaterial progross of the United States into more prominent light than a retrospectivo view of the condition of affairs forty years ago, in regard to the capacities of our mechanics to produce niachinery. In 1828, the first locomotive was imported from lingland, to draw the eoal-cars on the Carbondale and Ionesdalo Railroad, Pa.; tho second in 1830, to run passenger-cars on tho Mohawk and Hudson Railroad. The first American locomotive was built in 1830, in the United States Foundry, at West Point, for the South Carolina Railroad, and tho third in 1831, for the Mohawk aud Hudsou Railroad, which road was soon abandoned aud hroken up for want of patronage. In the sauic year Baldwin, of Philadelphia, ninde a miniature locomotivo, which conld draw two little cars with four persons; he exhibited it in Peale’s Musenm, iu Philadelphia, and this exhibition laid the foundation for his fortune, aud the largo machine shop in that city, still hearing his name. In the following year, he roceived au order from the Germantown Railroad Company to build a large Iocomotive. It would have frighteued any other man of less pluck, as in the wholo city thore were only five men who were ahle to help him, and no proper tools at all, Ile therefore commenced at once to make tools aud patterns, and, incredible as it seems, in six months the locomotive was rendy. It appears to have been a very delicate affair, as the advertisements in the Philadelphia papers of that day prove. They say, ‘‘Passengers to Germantown will go with a train of cars drawn hy the new engiue, when the weather is fair; when it raius, the horses will draw the cars.” Notwithstanding this, Baldwin’s reputation was settled; before the end of 1834, he had finished five locomotives. He was then able to fiuish two small ones in a year; now the same shop finishes one of large size, with tender, etce., every day. The first small locomotives could run with a velocity of ten miles an hour, and draw ene or two tons; the present locomotives have a speed of 40 miles per hour, and draw 1,000 tons. . A business commenced in 1831, with five men, without proper tools, in a smzll shop, (which still stands,) has increased in 1871 to a large manufaetory grown around it, occnpying a quarter of a million sqnare feet, employimg 2,000 men, and mauufacturing four milliou dollars worth oflocomotives per year, which are sent to California, Canada, South America, Europe, etc., in spite of Enropean competition, of cheap labor, and cheap material.— Manufacturer and Builder. Experiments with Lubricators, A very elaborate sories of experiments were recently mado in New York to test the relative value of different lubricators. The experiments were continued during a period offourteen months. The following were the general results and inferences: The consumption of oil varies with its temperature when applied. 7 Winter sperm oil, sustained the heaviest pressure, and was taken as the initial of comparison for all others, and their per eent. of Inbricating value determined by it. ‘The tests of mineral oils and mixtures of animal and fish oils with them wonld uot snstain an equal pressure with the sporm, when eqnal quantities of the oil were applied, without rapidly increasing the tomperatnre of the journals, and producing an abrasion of their surfaces. When the pressure on the boarings were made equal with winter sperm, it required from 100 to 400 per cent. increase of oil, to

keep the temperature of the journals below 100° Fahr, Experiments were made at varied velocites, with the same oils. The results proved that as the volocity was reduced the pressnre could be increased, and the relative consumption of oil, applied at equal temperatures, was decreased in almost equal ratio, §clENTIFIC Progress. Meteorites—Their Orbits, Ete. Mnch attention has of late years heen given to that erratio class of heavenly hodies known as meteors, or,,as they are sonletimes called, shooting stars. In raro instances theso hodies reaoli the earth, and when they do, they are usnally called aorolites, or motooric. stoues, from the character of their composition, Thoso which reach tho earth are not snpposed to he in any way ditferent from those which merely blaze out for an iustant, or shoot across a portion of the heavens, leavinff a hright train of light hehind,. When they fall to the earth, their direction is snch as to lead to an unavoidahle collision; those which hecome visible, for a moment only, and do not fall, enter into and pass through the upper and more rarifiod portions of the atmosphere, If their direction is such that they enter deeply into tho atmosphere, hnt not pointed directly to the earth’s surface, their motion isso much retarded by the friction of the air, that their direction is sufficiently changed by gravitation to bring them to the earth, and thus ond their existence as separate and distinct bodies in space. Meteors are of all sizes, from those of a few grains in weight to those of many pounds or even tons. The former, on entering deeply into the atmosphere, are rapidly dissipated by the great heat which is created by their friction, and the consnming effect of the oxygen with which they come in contact. The larger ones are usually fraetnred hy the groat heat produced upon their surface, aud fall in fragments to the carth. Their fracture is usually attended by coneussion, which often sounds like the report of distant canton. The continued, subdued roaring which is often heard during their flight across the heavens in their approach to’the earth, is produced by the rushing past them, laterally, of the air, which falls rapidly in hehind them, to fill the partial vacuum caused by their motion. It has been calenlated that not less than an average of seven millious of meteors might he seen from all parts of the earth, every twenty-four hours, provided the earth shonld move dnring that time through a elear sky, withont any light from the snn or moon. If all the meteors which so pass the earth within the time specitied could be brought into the field of a telescope, it is calenlated, on reliable authority, that the number would reach fully fonr hundred millions! All these hodies move around the sun, and late observations have established the fact that many, if not most of them, move in approximately concentrated orbits, like the asteroids; but unlike the asteroids, in extremely elliptical orbits, like comets, The path of the ‘‘ November meteors” has its aphelion just beyond the orbit of Uranus, and its perhelion at or near the earth’s orbit, and inclined about 17 degrees to that of the earth. Careful observations have lcd to the snpposition that there are at least fifty different rings of meteors, such as the November ring, of which, however, that is by far the most extensive. Chemical analysis has revealed the presence of at least twenty-three different elements in these meteors, ont of the whole number of sixty five thus far discovered as composing the earth’s substance. The names of these elemeutsare asfollows: Oxygen, hydrogen, nitrogen, sulphur, phosphorus, carbon, silicon, nickel, chromium, tin, aluminum, magnesinm, calcium,’ potassium, sodium, eobalt, manganese, iron, copper, titanium, lead, lithium and strontium. The prosence of these elements, found also in the earth, suggests a common origin. The asteroids probably compose a“ ring” very similar to the November meteors; but its great distance from the earth will not admit of any except its larger component parts being scen, even by the telescope. No doubt a closer view would reveal an almost illimitable number, even down to bodies not greater than the larger asteroids. These bodies are supposed to be either the fragments of an exploded planet, or a planetary body thrown off from the sun in the form of aring, and aggregated into a great number of small bodies, instead of into one large body, like the earth and other planets. — , From the eecentrity of the orbits of the meteorites, wemight perhaps suppose them to he fragmentary portions of a cometary body, widely scuttered in space, instead of beiug eoucentrated into a single body, as are the hodies kuowu as coniets, The spectrum, that wonderful instrument of eomparatively reeent discovery, which is jnst beginning to be employed in the observation of comets, appears to indicate that these erratic bedigs ure composed of gases at a very clovated tempcratnre. A cureful microscopie study of mauy of the asteroids which have fallen to the earth, shows most conclusively that these bodies have at some titue heen in a state of vapor —as tho comets now arc—and that proximately they are nade np of smull rounded globnies, which have accumulated and been more or less fractured hy mutual impact, and finally consolidated, ‘I'bese snpposed facts would seem to indieato a eommon origin for comets and meteors. Action or SuLpaurous Acip on PxHosrHates.—B. W. Gerland has heen making some important experiments on the action of aqueons sniphnrous acid upon phosphates, which havo developed some points of great practical importance, especially in their bearing on tho manufacture of artificial composts and solnble phosphates. He finds that aqueons sulphurous acid does not, like the strong acids, wholly decompose the phosphates, but transforms them into soluble modificutions, The ordinary bone phosphate, called tribasic, is easily soluhle in sulphurous acid, and if the solution he hastily boiled and evaporated in open vessels, a crystalline duuble salt, 2 wixtnre of trihasie phosphate with a sulphate of lime, will separate. This new aed remarkahlo body is said to be quite permanent, and in reference to its nse as a disinfectant, aud upou farm land it is certainly deserving of special notice. If we can by means of sulphurous acid decompose the phosphates, we shall avoid the expense of sulphurio acid, which must first he made from snlphurons acid, and obtain a product not so difficult to handle, and capable of a greater variety of uses than the superphosphates made in the eld way. Mr. G. has studied the behavior of sulphurons acid towards other phosphates, the resnIts of which, however, being purely theoretical we omit them. Brome or Porassrum.—The increasing use of bromide of potassium, another of chemistry’s contributions, would have been impossihle, were it not for the extraordinary diseovery of an apparently evaporated sea water hed iu Germany. The amount of bromide consnméd in medicine is dow enormons, aud most of it is derived from this source. The same mines have also completely changed our sonrces of potash; they produce far more than all the other sources of England and France pnt together, and have so reduced the price tbat carbonate of potash is now largely made in England at a price which competes most favorably with American pearlash, and will ultimately drive it out of that market. Bromide of potassium isan iystance of a snbstance long used in meilicine before its valnahle properties werd discovered. Inganation or Dust ny Worxmen.— The injurious effect of exposure to the dust of varions manufacturing establishments has not unfrequently been dwelt upon with more or less force; but we are hardly prepared for the resnlt of certain specific investigations on this subject, It has long been a dispnted point whether the particles of iron, silica, etc., mercly lodge within the air-cells of the Inngs, or penetrate through their walls into the tissue between them. But Professor Zenker informs us that, on examining the Inngs of a woman who had been exposed to the dust of iron oxide, used in preparing books of gold-leaf, he fonnd the powder in the tissne between the air-cells and in their walls, as well as in their cavities. From less than two ounces of this lung over twelve grains of iron oxide were obtained by chemical mothods; so that, if equally distributed through both lungs, there must have heon at least three-quarters of an ounce inhaled. In another case—that of a workman exposed to the dust of a mixture used in preparing ultramarine substances—he found a quantity estimated at fully an ounce.—AHarper's Magazine. M. Deverciz, a French chemist, finds that water containing only one fonr thousandth of its weight of carbolic acid sufficed for the disinfection of the Morgue in Paris during the hottest weather, when it contained six or seven bodies,