Volume 15 (1867) (424 pages)

Che Mining and Scientific Lress. 3 Mechanical. Steam vs. Hand Labor. When stcam power first began to supersede band labor in England, the forebodings of the workmen were terrible. So with the early introduction of labor-saving macbines in general, botb in England aud on tbis continent In England, the contest was a hard one. The lahorers fought against sucb improvements with an ardor and perseverance which are exhibited only when men aro figbting for a footbold upon exististence. How short-sighted they were, and how baseless were their forebodings, has been abundantly proven by tho sequel. The opening thereby made for educated and skillod lnhor has elevated the mechanic from the condition of a mere serf to that of the highest position in the social scale. The steam engine has proven the great civilizer of the age, and has completely broken down the wide distinction tbat once existed botween the laborer and the tradesman or professional man. The genius of the akillful and intelligent mechanic has now no limit; while tbe avenues of wealth and fame are as open and promising to him as to that of any other member of society. The time was when pcople helieved that ‘*all the intelligence,” says the Boston Jnvestigator, came from within the walls of a collogiate institution—that men, to be qualified to hold offices of trust and emolnment, must first ‘‘ graduate.” But tbat idea bas exploded. The cfiicient men of to-day are those who never had a *‘liberal” education ; but those who have, are the most bigoted and illiberal among us, with a few honorable exceptions. The workshop produces the free mind, the potency of which is being everywhere felt, to the utter dismay of every grade of fogyism. By the aid of improved machinery, one man can now spin four hundred times more cotton yarn than the hest cotton-spinner eould in 1769, when Arkwright took out his first patent. In grinding grain aud making flour, one man can now do one hundred and fifty times more work than he could a century ago. One woman can now manufacture a3 much lace in a day as a hundred women could a hundred years ago. It now reqnires as many days to refine sugar as it did months thirty years ago. Only forty minutes are now required to fix an amalgam of mereury and tin on a large looking-glass, which once occupied aix weeks. The engines of a first-class ironclad frigate perform as much work in twenty-four hours as 42,000 horses, Saw Teeta.—The number of saw teeth should be proportioned both to hardness of the timber to be sawed and tho power to be used. Each tooth of a saw can only cut advantageously a certain distance forward in passing through the log, which distance depends on tho hardness of the wood; but if a saw has too many teeth, or is driven by too weak a power, each tooth will not cut so far forward as it ahould do, and there is a loss of power. If the power is great; and tho numher of teeth fow, then each tooth will have to cut too far forward. Awertoan Inon,—Just previons to the breaking out of the war, an important experiment was made in Georgia to test the relative durability of American and English railroad iron. A portion of the track of the Central Railroad, subjected to great wear, was laid—one side with American and tbe other with Englishiron. At tho expiration of two years, the wear was decidedly in favor of the American iron, PROPELLERS AND SIDE-WHEELS.—Al] the American steamships sailing from New York to European ports have side-wheels ; while all except four or five of the forcign ships have screw propellers. A new line of American steamers about to be started from Boston will have acrew propellers. MEcHANIOAL cultivation of the land ia attracting great attention in France. Anririctat Woop. —An important branch of industry bas recently sprnng up in Rhenisb Prussia. It consists in the manufacture of various articles from refuse wood and saw dnst, which are agglomerated hy a cement, the exact nature of which is not stated, and then pressed in molds, so as to form covers for pbotographic albums, small picture frames, rosettes, and other ornaments for the use of cahinet-makers, etc. For the last mentioned articles the composition is stained to imitate ehony, mabogany, walnut and other woods. The composition, or ‘‘scrifarine,” as it is called, may be sawn, cut, drilled, attached together hy glue, aud bent on hot plates. It may ho polished with oil or French polish, and may be varnished and gilt. A similar composition was;manufactured in France, a few years ago, hy mixing fine saw dust with Dlood and submitting it to the action of a hydraulic press.— London Builder. The above paragraph comes to us from Europe as something new, hut we helieve the very same branch of industry has heen estahlished in this country for several years. Saw dust has been comhined with shellac, colored with various pigmeuts, and pressed in molds, whicb were heated to the neccssary degree to melt the shellac. The principal use made of this compositiou was the manufacture of ambrotype cases and small picture-frames, hut an application of it was made in the form of huttons, chessmen, ete. It is a good imitation of vulcanized rubber, but it will not sustain the wear and rough usage which the ruhber will bear.—American Artisan. A NEW KIND OF FIRE-PROOF is descrihed by the Idaho J¥orld as follows: While at Centreville, the other day, we were shown a novel kind of fire-proof above-ground cellar, belonging to and in the rear of the store of Duke & Co. The iuner walls are of wood—ordinary plank. Against these upon the outside are the novel and perfectly fire-proof walls, made of mere dry earth mixed with molasses, with short cut fibers of old rope, to serve as bair in plastering, included in the mixture. When prepared, this strange plastering is spread on the hoards, with a heavy plauk to retain tbe mixture in the place intended, and theu a big maul is hrought to play upon the plank to beat the mixture solidly in. This is the process, and it is repeated, layer upon layer, and width upon widtb, until tbe whole mass is two feet thick and entircly envelopes the building. A roof of the samo material, put on the same way, is added, and the building or cellar is completed. The cellar of Duke & Co. has heen finished only a few days, and yet this covering of dry earth, molasses and hempen fiber is so bard that 2 nail cannot be driven into it, . . and it is impervious to either fire or water. it is an invention of Mr. J. B. Duke’s, aud though a good many laughed at him, and tried to convince him, while he was puttiug on the queer mixture, that it would he a signal failuro, all now admit that his head was the soundest on that, and all agree that it is a model fire-proof cellar he has made. Stern Coorrme UrTensris.—Bessemer’s steel is recommended for cooking utensils. The material is not acted on by the various agents which attack copper, and thus on the score of health and safety it possesses special recommendations.” Over cast iron for saucepans, ote., it will have the further adthinner, a great saving of heating material will be effected. The rolled sheets of steel may, by the aid of a lathe, be pressed into any required form, and thus the vessel is constructed of oue piece, requiring no rivets or soldering. Various household utensils have already been macle of this steel. Praster oF Parts—AcerentaL DiscovERY.—The discovery tbat plaster of paris was a non-conductor of heat was made by a man who, while making plaster images, frequently washed his hands in a tiu pan, the hottom of which soou became incrusted. Soou after, when it was put ou the fire to heat water, it was found tbat the water could not be heated. This discovery was put to a practical use in the making of iron safes, tbe chambers of which aro filled with plaster, which, in case of fire, prevents the contents from being burned. CASE-HARDENING Inon.—Cast iron may be case-hardened by heing rolled at a red heat in equal parts of powdered prussiate of potash, saltpetre and sal-ammoniac, and by being then placed, whilst yet hot, in a bath containing two ounces of prussiate of potash and four ounces of sal-ammoniac in every gallon of cold water. A SELF-PROPELLING steam fire engine has been completed in Manchester, N. H., and made a succeaaful trip through the atreets. Srientitic Misreliany. Facts wird Recarp ro Fvsv.—Wood is the most bealthy fuel to burn, from the fact tbst it gives off the least noxious gas, and contains the largest amount of oxygen. Coal contains but very little or no oxygen; bence the oxygen necessary for its consuniptiou must be extracted from the atmosphere. So witb coal oil, which is a very unhealthy fuel, except when hurned in well ventilated rooms. burned in a close room, the air will soon heeome ‘‘oppressivo”—it will have been deprived of a large percentage of its oxygen. A coal fire will soon go ont unless it has alarge supply of air (oxygen), while wood will burn with’ comparatively little air, having a large supply of oxygen within itself, Hard, close-grained wood is converted into ‘‘live” coals ; soft, porous wood into ashes. Close-grained, beavy woods, like hickory and oak, give out the most heat; although the lighter woods, such as pine and willow, being open-grained, heat up much tbe quickest. . The relative value of the different fuels is determined by the amount of water which a pound thercof will raise toa given temperature. Thus, one pound of dry wood will convert forty pounds of ice into boiling water; while a pound of good coal will raiso eighty pounds of ice to the hoiling point of water—bence, one pound of coal is worth two pounds of dry wood. A ton of coal at ten dollars is equal to two cords of wood at five dollars per cord. It would be more cquitahle to sell wood by the ton, when dry, the same as coal. Such, indeed, is the custom in some portions of Europe. Vocat Macuinery or Brps.—Uutil receutly, it was quite difficult to account for so smalla creature as a bird, especially a canary bird, making a tone as loud as some animals a thousand times the weight of that bird. Recent discoveries, however, have shown that in birds the lungs have several openiugs communicating with corresponding air-bags or cells, which fill the whole cavity of the body from the neck downwards, and into which the air passes and repasses in the progress of breathing. This is not all; the very bones are hollow, from which air-pipes are conveyed to the most solid parts of the body, even into the quills and hody. By-foreing the air out of the body, they can dart to the greatest hight with astonishing velocity. No doubt the same machinery forms the basis of their vocal powers, and at once aolves the mystery. . INFLAMMABILITY OF THoRovcHLY Damp Woov.—Scientifie writers iuform us that d, wh tinually exposed to a ver vantage tbat, as the vessels are so much Re ia se y moderate heat, such as that of steam and hot water pipes, will, in a space of time varying from eight to ten years, become so inflammable that it will take fire ata température very little over that of hoiling water. The wood undergoes a slow process of charring, and, it is said, only awaits the admission of air (which it gets by shrinking aud cracking) to burst out into flame. Tur Resunts of Scmner.—Agassiz was oncs presented with a single scale of an unknown fish. From tbe study of that seale he made a drawing of the appearance which the fish to svhich that scalo belonged must have made. A fish, corresponding almost. precisely with his drawing, and haying identically the same scale, was subsequently found, thereby proving the correctness of the deductiona of science. Tse phenomena of sound gives the key to the modern theory of the propagation of light; hoth being produced by vibration— of sound in the air and of light in a much more subtle suhstance penetrating the universe, The musical scale corresponds to the seale of prismaticcolors. In light there are different octaves, such as the caloric, the Iuminons, the chemical, ete. If cither coal or oil is’ _ ARTIFICIAL AGATE. —Agate when polished is sometimes seen to hear markings which . have a curious resemblance to a variety of . natural ohjects, such as trees, bushes, and ‘occasionally animals, These natural ap. pearances, it seems, may be casily imitated . artificially in various shades of color on ‘common chaleedony. It is only necessary to draw the design on the polished stoue, using &2common goose quill, with tolerably strong solution of nitrate of silver, and then drying it in direet sunligbt. The drawing will at first he of a hrownish color, hut if dricd and touched over two or three times it will he reddish. The same solution of nitrate of silver mixed with 1214 per cent. of soot and 12% per cent. of bitatrate of potash will give a greyish-brown color. A violet color may be ohtained by mixing one part of alum with three parts of the silver solution. Gold dissolved in aqua regia, or a solution of chloride of gold, gives a light-brown color. White and opaque appearances will he giveu hy a solution of nitrate of bismuth. All these colors are unaffected by the atmospbere, and will bear wasbing. They can, in fact, only he destroyed by a very high temperature. They may he discharged hy treatment with strong acids, but will reappear after wasbing anda fresb exposure to sunlight.—Jechanics’ Magazine, _AtmosPHERIO Action. —Tbe carbonic acid of tbe air slowly attacks the rocks above the ocean level, and thus turns them to clay, forming carbonates with tbe soda, potash, lime and magnesia, set free, and carries these dowu as carhonates to the sea, where the carhonate of soda decomposes the chloride of calcium of its waters, and forms common salt and carhonate of lime. This scries of actions is the source of the salt of the sea, of all clays and of limestones which are chemical and not organic in their origin. Organic living things do not generate the carbonate of lime, but appropriate it, when found for them by chemical reactions; and thus great portions of our limestone rocks are made up of fossil remains. In fortyfour feet of limestone, there is separated and condensed from tho air a large atmosphere of carbonic acid gas; the early atmospbere was therefore very dense and unfit for the sustenance of the higher forms of life, until by far the greater portion of this gas bas, been removed by the formation of thé carbonate of lime and vegetable matter now constituting coal and petroleum, To Pruxt Lerrers sy Sunnicur.—Dissolve chalk in aquafortis to the consistence of milk, and add to that a strong solution of silver. Keep this liquor in a glass decanter well stopped, then cut out from a paper the letters you would have appear, and paste the paper on the decanter, which you are to place in auch a manner that its rays may pass through the places cut out of the paper and fall on the surface of the liquor. The part of the glass through which the rays pass will turn black, while that under the paper will remain white. You must observe not to move the bottle during the time of the operation.—Chemical News. OxmatTion py Means or CHarcoan.—A communication was lately read at the London Chemical Society concerning experiments made with recently-burned boxwood charcoal. It was first placed in pure oxygen gas, and, after being saturated into other gases and vapors, and the absorption as well as the resulting vapors were noted. Moist sulphurous acid and aulphureted hydrogeu were changed to aulphuric acid; common alcohol to acetic acid, amylic alco hol to valerianic acid; but the author asserted that ammonia does not undergo oxidation in the pores of charcoal. InnusmnaTine 0as is said to be considerably increased in power by heating it and buruing it with heated air. It would not be difficult or expensive to put up gas and air pipes, ot a double pipo for both, in connectiou with household furnaces, ete., and apply combination burners. Enewentary Comprvations.—The moat delicious fruits are composed of hydrogen, oxygen, carbon and nitrogen ; and the most deadly poisons are composed of the aame ingredients, differing only in the proportions of their combination.A Sure Rouz.—To ascertain the length of the day or night, at any time of the year, double the time of the sun’a rising, which gives you tho length of the nigbt, and double the timo of its setting, which givea the leugth of the day. Vanaprum.—Mr. Mushet has expressed the opinion that a minute quantity of tbe metal vanadium mixed with iron forms a valuahlo alloy, and gives a fine, tough, . fibrous texture to har iron.

Che Mining and Scientific Lress. 3 Mechanical. Steam vs. Hand Labor. When stcam power first began to supersede band labor in England, the forebodings of the workmen were terrible. So with the early introduction of labor-saving macbines in general, botb in England aud on tbis continent In England, the contest was a hard one. The lahorers fought against sucb improvements with an ardor and perseverance which are exhibited only when men aro figbting for a footbold upon exististence. How short-sighted they were, and how baseless were their forebodings, has been abundantly proven by tho sequel. The opening thereby made for educated and skillod lnhor has elevated the mechanic from the condition of a mere serf to that of the highest position in the social scale. The steam engine has proven the great civilizer of the age, and has completely broken down the wide distinction tbat once existed botween the laborer and the tradesman or professional man. The genius of the akillful and intelligent mechanic has now no limit; while tbe avenues of wealth and fame are as open and promising to him as to that of any other member of society. The time was when pcople helieved that ‘*all the intelligence,” says the Boston Jnvestigator, came from within the walls of a collogiate institution—that men, to be qualified to hold offices of trust and emolnment, must first ‘‘ graduate.” But tbat idea bas exploded. The cfiicient men of to-day are those who never had a *‘liberal” education ; but those who have, are the most bigoted and illiberal among us, with a few honorable exceptions. The workshop produces the free mind, the potency of which is being everywhere felt, to the utter dismay of every grade of fogyism. By the aid of improved machinery, one man can now spin four hundred times more cotton yarn than the hest cotton-spinner eould in 1769, when Arkwright took out his first patent. In grinding grain aud making flour, one man can now do one hundred and fifty times more work than he could a century ago. One woman can now manufacture a3 much lace in a day as a hundred women could a hundred years ago. It now reqnires as many days to refine sugar as it did months thirty years ago. Only forty minutes are now required to fix an amalgam of mereury and tin on a large looking-glass, which once occupied aix weeks. The engines of a first-class ironclad frigate perform as much work in twenty-four hours as 42,000 horses, Saw Teeta.—The number of saw teeth should be proportioned both to hardness of the timber to be sawed and tho power to be used. Each tooth of a saw can only cut advantageously a certain distance forward in passing through the log, which distance depends on tho hardness of the wood; but if a saw has too many teeth, or is driven by too weak a power, each tooth will not cut so far forward as it ahould do, and there is a loss of power. If the power is great; and tho numher of teeth fow, then each tooth will have to cut too far forward. Awertoan Inon,—Just previons to the breaking out of the war, an important experiment was made in Georgia to test the relative durability of American and English railroad iron. A portion of the track of the Central Railroad, subjected to great wear, was laid—one side with American and tbe other with Englishiron. At tho expiration of two years, the wear was decidedly in favor of the American iron, PROPELLERS AND SIDE-WHEELS.—Al] the American steamships sailing from New York to European ports have side-wheels ; while all except four or five of the forcign ships have screw propellers. A new line of American steamers about to be started from Boston will have acrew propellers. MEcHANIOAL cultivation of the land ia attracting great attention in France. Anririctat Woop. —An important branch of industry bas recently sprnng up in Rhenisb Prussia. It consists in the manufacture of various articles from refuse wood and saw dnst, which are agglomerated hy a cement, the exact nature of which is not stated, and then pressed in molds, so as to form covers for pbotographic albums, small picture frames, rosettes, and other ornaments for the use of cahinet-makers, etc. For the last mentioned articles the composition is stained to imitate ehony, mabogany, walnut and other woods. The composition, or ‘‘scrifarine,” as it is called, may be sawn, cut, drilled, attached together hy glue, aud bent on hot plates. It may ho polished with oil or French polish, and may be varnished and gilt. A similar composition was;manufactured in France, a few years ago, hy mixing fine saw dust with Dlood and submitting it to the action of a hydraulic press.— London Builder. The above paragraph comes to us from Europe as something new, hut we helieve the very same branch of industry has heen estahlished in this country for several years. Saw dust has been comhined with shellac, colored with various pigmeuts, and pressed in molds, whicb were heated to the neccssary degree to melt the shellac. The principal use made of this compositiou was the manufacture of ambrotype cases and small picture-frames, hut an application of it was made in the form of huttons, chessmen, ete. It is a good imitation of vulcanized rubber, but it will not sustain the wear and rough usage which the ruhber will bear.—American Artisan. A NEW KIND OF FIRE-PROOF is descrihed by the Idaho J¥orld as follows: While at Centreville, the other day, we were shown a novel kind of fire-proof above-ground cellar, belonging to and in the rear of the store of Duke & Co. The iuner walls are of wood—ordinary plank. Against these upon the outside are the novel and perfectly fire-proof walls, made of mere dry earth mixed with molasses, with short cut fibers of old rope, to serve as bair in plastering, included in the mixture. When prepared, this strange plastering is spread on the hoards, with a heavy plauk to retain tbe mixture in the place intended, and theu a big maul is hrought to play upon the plank to beat the mixture solidly in. This is the process, and it is repeated, layer upon layer, and width upon widtb, until tbe whole mass is two feet thick and entircly envelopes the building. A roof of the samo material, put on the same way, is added, and the building or cellar is completed. The cellar of Duke & Co. has heen finished only a few days, and yet this covering of dry earth, molasses and hempen fiber is so bard that 2 nail cannot be driven into it, . . and it is impervious to either fire or water. it is an invention of Mr. J. B. Duke’s, aud though a good many laughed at him, and tried to convince him, while he was puttiug on the queer mixture, that it would he a signal failuro, all now admit that his head was the soundest on that, and all agree that it is a model fire-proof cellar he has made. Stern Coorrme UrTensris.—Bessemer’s steel is recommended for cooking utensils. The material is not acted on by the various agents which attack copper, and thus on the score of health and safety it possesses special recommendations.” Over cast iron for saucepans, ote., it will have the further adthinner, a great saving of heating material will be effected. The rolled sheets of steel may, by the aid of a lathe, be pressed into any required form, and thus the vessel is constructed of oue piece, requiring no rivets or soldering. Various household utensils have already been macle of this steel. Praster oF Parts—AcerentaL DiscovERY.—The discovery tbat plaster of paris was a non-conductor of heat was made by a man who, while making plaster images, frequently washed his hands in a tiu pan, the hottom of which soou became incrusted. Soou after, when it was put ou the fire to heat water, it was found tbat the water could not be heated. This discovery was put to a practical use in the making of iron safes, tbe chambers of which aro filled with plaster, which, in case of fire, prevents the contents from being burned. CASE-HARDENING Inon.—Cast iron may be case-hardened by heing rolled at a red heat in equal parts of powdered prussiate of potash, saltpetre and sal-ammoniac, and by being then placed, whilst yet hot, in a bath containing two ounces of prussiate of potash and four ounces of sal-ammoniac in every gallon of cold water. A SELF-PROPELLING steam fire engine has been completed in Manchester, N. H., and made a succeaaful trip through the atreets. Srientitic Misreliany.

Facts wird Recarp ro Fvsv.—Wood is the most bealthy fuel to burn, from the fact tbst it gives off the least noxious gas, and contains the largest amount of oxygen. Coal contains but very little or no oxygen; bence the oxygen necessary for its consuniptiou must be extracted from the atmosphere. So witb coal oil, which is a very unhealthy fuel, except when hurned in well ventilated rooms. burned in a close room, the air will soon heeome ‘‘oppressivo”—it will have been deprived of a large percentage of its oxygen. A coal fire will soon go ont unless it has alarge supply of air (oxygen), while wood will burn with’ comparatively little air, having a large supply of oxygen within itself, Hard, close-grained wood is converted into ‘‘live” coals ; soft, porous wood into ashes. Close-grained, beavy woods, like hickory and oak, give out the most heat; although the lighter woods, such as pine and willow, being open-grained, heat up much tbe quickest. . The relative value of the different fuels is determined by the amount of water which a pound thercof will raise toa given temperature. Thus, one pound of dry wood will convert forty pounds of ice into boiling water; while a pound of good coal will raiso eighty pounds of ice to the hoiling point of water—bence, one pound of coal is worth two pounds of dry wood. A ton of coal at ten dollars is equal to two cords of wood at five dollars per cord. It would be more cquitahle to sell wood by the ton, when dry, the same as coal. Such, indeed, is the custom in some portions of Europe. Vocat Macuinery or Brps.—Uutil receutly, it was quite difficult to account for so smalla creature as a bird, especially a canary bird, making a tone as loud as some animals a thousand times the weight of that bird. Recent discoveries, however, have shown that in birds the lungs have several openiugs communicating with corresponding air-bags or cells, which fill the whole cavity of the body from the neck downwards, and into which the air passes and repasses in the progress of breathing. This is not all; the very bones are hollow, from which air-pipes are conveyed to the most solid parts of the body, even into the quills and hody. By-foreing the air out of the body, they can dart to the greatest hight with astonishing velocity. No doubt the same machinery forms the basis of their vocal powers, and at once aolves the mystery. . INFLAMMABILITY OF THoRovcHLY Damp Woov.—Scientifie writers iuform us that d, wh tinually exposed to a ver vantage tbat, as the vessels are so much Re ia se y moderate heat, such as that of steam and hot water pipes, will, in a space of time varying from eight to ten years, become so inflammable that it will take fire ata température very little over that of hoiling water. The wood undergoes a slow process of charring, and, it is said, only awaits the admission of air (which it gets by shrinking aud cracking) to burst out into flame. Tur Resunts of Scmner.—Agassiz was oncs presented with a single scale of an unknown fish. From tbe study of that seale he made a drawing of the appearance which the fish to svhich that scalo belonged must have made. A fish, corresponding almost. precisely with his drawing, and haying identically the same scale, was subsequently found, thereby proving the correctness of the deductiona of science. Tse phenomena of sound gives the key to the modern theory of the propagation of light; hoth being produced by vibration— of sound in the air and of light in a much more subtle suhstance penetrating the universe, The musical scale corresponds to the seale of prismaticcolors. In light there are different octaves, such as the caloric, the Iuminons, the chemical, ete. If cither coal or oil is’ _ ARTIFICIAL AGATE. —Agate when polished is sometimes seen to hear markings which . have a curious resemblance to a variety of . natural ohjects, such as trees, bushes, and ‘occasionally animals, These natural ap. pearances, it seems, may be casily imitated . artificially in various shades of color on ‘common chaleedony. It is only necessary to draw the design on the polished stoue, using &2common goose quill, with tolerably strong solution of nitrate of silver, and then drying it in direet sunligbt. The drawing will at first he of a hrownish color, hut if dricd and touched over two or three times it will he reddish. The same solution of nitrate of silver mixed with 1214 per cent. of soot and 12% per cent. of bitatrate of potash will give a greyish-brown color. A violet color may be ohtained by mixing one part of alum with three parts of the silver solution. Gold dissolved in aqua regia, or a solution of chloride of gold, gives a light-brown color. White and opaque appearances will he giveu hy a solution of nitrate of bismuth. All these colors are unaffected by the atmospbere, and will bear wasbing. They can, in fact, only he destroyed by a very high temperature. They may he discharged hy treatment with strong acids, but will reappear after wasbing anda fresb exposure to sunlight.—Jechanics’ Magazine, _AtmosPHERIO Action. —Tbe carbonic acid of tbe air slowly attacks the rocks above the ocean level, and thus turns them to clay, forming carbonates with tbe soda, potash, lime and magnesia, set free, and carries these dowu as carhonates to the sea, where the carhonate of soda decomposes the chloride of calcium of its waters, and forms common salt and carhonate of lime. This scries of actions is the source of the salt of the sea, of all clays and of limestones which are chemical and not organic in their origin. Organic living things do not generate the carbonate of lime, but appropriate it, when found for them by chemical reactions; and thus great portions of our limestone rocks are made up of fossil remains. In fortyfour feet of limestone, there is separated and condensed from tho air a large atmosphere of carbonic acid gas; the early atmospbere was therefore very dense and unfit for the sustenance of the higher forms of life, until by far the greater portion of this gas bas, been removed by the formation of thé carbonate of lime and vegetable matter now constituting coal and petroleum, To Pruxt Lerrers sy Sunnicur.—Dissolve chalk in aquafortis to the consistence of milk, and add to that a strong solution of silver. Keep this liquor in a glass decanter well stopped, then cut out from a paper the letters you would have appear, and paste the paper on the decanter, which you are to place in auch a manner that its rays may pass through the places cut out of the paper and fall on the surface of the liquor. The part of the glass through which the rays pass will turn black, while that under the paper will remain white. You must observe not to move the bottle during the time of the operation.—Chemical News. OxmatTion py Means or CHarcoan.—A communication was lately read at the London Chemical Society concerning experiments made with recently-burned boxwood charcoal. It was first placed in pure oxygen gas, and, after being saturated into other gases and vapors, and the absorption as well as the resulting vapors were noted. Moist sulphurous acid and aulphureted hydrogeu were changed to aulphuric acid; common alcohol to acetic acid, amylic alco hol to valerianic acid; but the author asserted that ammonia does not undergo oxidation in the pores of charcoal. InnusmnaTine 0as is said to be considerably increased in power by heating it and buruing it with heated air. It would not be difficult or expensive to put up gas and air pipes, ot a double pipo for both, in connectiou with household furnaces, ete., and apply combination burners. Enewentary Comprvations.—The moat delicious fruits are composed of hydrogen, oxygen, carbon and nitrogen ; and the most deadly poisons are composed of the aame ingredients, differing only in the proportions of their combination.A Sure Rouz.—To ascertain the length of the day or night, at any time of the year, double the time of the sun’a rising, which gives you tho length of the nigbt, and double the timo of its setting, which givea the leugth of the day. Vanaprum.—Mr. Mushet has expressed the opinion that a minute quantity of tbe metal vanadium mixed with iron forms a valuahlo alloy, and gives a fine, tough, . fibrous texture to har iron.