페이지 이미지
PDF
ePub

secret on me, but in vain. He this act,” said he, “ it is quite asked me for a piece of gold, and otherwise; for unless thou knowopening his doublet, showed me est the thing from head to heel,, five pieces of that precious metal, thou canst not break open the which he wore on a green ribbon, glassy seal of Hermes. Butenough: and which very much excelled to-morrow, at the ninth hour, I mine in flexibility and colour, each will show thee the manner of probeing the size of a small trencher. jection.” But''Elias never came I now earnestly again craved a again; so my wife, who was cucrumb of the stone, and at last, out rious in the art whereof the worof his philosophic commiseration, thy man had discoursed, teased he gave me a morsel as large as a me to make the experiment with the rape seed; but, I said, “ This little spark of bounty the artist had scanty portion will scarcely trans- left me; so I melted half an ounce mute four grains of lead.” “Then,” of lead, upon which my wife put said he, « deliver it me back ;" the said medicine. It hissed and which I did, in hopes of receiving bubbled, and in a quarter of an a greater parcel ; but he, cutting bour the mass of lead was transoff half with his nail, said, “ Even muted into fine gold, at which we this is sufficient for thee.” “Sir,” were exceedingly amazed. I took it said I, with a dejected counte- to the goldsmith, who judged it nance, “ what means this?” And most excellent, and willingly offerhe said, “ Even that will transmute ed me fifty florins for each ounce. half an ounce of lead.” So I gave Brand's Manual of Chemistry. him great thanks, and said I would try it, and reveal it to no one. He then took his leave, and said he w

SUBSTITUTE FOR COCHIwould call again the next morning

NEAL. at pine. When he returned, I con In the steppes of the Ukraine fessed that I had scraped off a bit there grows in great quantities a with my nail, when the substance plant, named polygonum minus, which was in my hand, which I had project is gathered at the end of July ; it ed in lead, but it caused no trans- is torn up by the roots, which conmutation ; for the whole flew away tain a species of maggot, or ipsect, in fumes. “ Friend,” said he, of an oval shape, and which hard“ Thou art more dexterous in com- ens by being exposed to the air. mitting theft than in applying me. They are put into a certain quandicine. Hadst thou wrapped up tity of water, with the addition of a thy stolen prey in yellow wax it little alum; and this water becomes, would have transmuted the lead after a short time, of a most beauinto gold.” I then asked if the tiful scarlet colour. The Cossack philosophic work cost much, or women, who sell it to the Russian · required long time, for philosophers merchants, dye their thread with it, say that pine or ten months are and likewise use it to paint themrequired for it. He answered, selves. The Polish Jews and the “Their writings are only to be un- Armenians sell a great deal of it derstood by the adepts, without to the Turks, who use it to dye whom no student can prepare this their silks, to make morocco leamystery. Fling not away, therefore, ther, and to dye the tails and thy money and goods in hunts manes of their horses ; they even ing out this art, for thou never dye their own hair, their beards, shall find it.” To which I replied, and their nails with it. They call “ As thy master showed it thee, so this maggot coceus polonicus. Acmayest thou perchance discover cording to an experiment made at something thereof to me, who Moscow, a pound of these magknow the rudiments; and, there- gots, which costs a rouble, profore, it may be easier to add to a duces as much colour as half a foundation than begin anew.” “In pound of cochineal.

som

TO PROCURE OXYGEN GAS, Or this gas may be obtained by

AND BURN STEEL. I putting black oxide of manganese OXYGEN gas, called also vital coarsely powdered into the retort, air, is one of the constituent parts A; pour upon it a sufficient quanof the atmosphere; and though, if tity of sulphuric acid to form a breathed entirely pure, it causes a liquid paste, and then apply the hurried and laborious respiration, heat of the lamp, and oxygen gas it is nevertheless essential to life. rises abundantly. Atmospheric air supports life from To collect this gas, take a comthe oxygen it contains. Oxygen also monearthenware bason,C,and place supports combustion ; with some across it a board of four or five few exceptions, its presence is ne inches wide, and about three quarcessary to combustion, and, in gene- ters of an inch thick, having a slit ral, other substances only aid com wide enough to pass the bottle, D, bustion from the quantity of oxygen through, terminating in a hole, so they contain. It is also one of the that the bottle will stand upright. constituent parts of water, and has The bason is to be filled with water, been named, though perhaps erro- and the bottle full of water is to be neously, from a supposition that it placed inverted in the hole. This was the acidifying principle. It is done by immersing the bottle in gives sourness to many compounds, the bason, and then placing it upbut not to all; it is a colourless right, without allowing the mouth clastic fuid, like common air, of the bottle to be ever out of the though somewhat heavier than it, water. When the bottle is thus and has neither smell nor taste; it placed, and the atmospheric air has is one of the substances the young been expelled from the retort, carchemist is earliest made acquainted ry its mouth through the water with, and with which, from its very into the mouth of the bottle; the great importance, he continues oxygen gas rises in bubbles to the most familiar; it may be produced top of the bottle and gradually disin several ways. We shall give a places the water. The bottle then description of two.

appears empty, but is, in fact, full To obtain it in the greatest pu- of oxygen gas. If it is required to rity, put two or three drachms of fill more bottles than one, a regular chlorate of potash, also called oxy- pneumatic apparatus is necessary, muriate of potash, into a glass which will be hereafter described. retort, A, capable of holding about In the mean time, having one bottwo ounces of water, and apply tle full, let us proceed to burn to it the heat of a spirit lamp, B. steel wire in it, one of the most The first portions of air which arise brilliant experiments of chemistry, must be rejected on account of their and which has been displayed to being mixed with the atmospheric numerous bodies of admiring specair of the vessel; but when the salt tators. is completely melted, oxygen gas Take a bit of steel wire, from rises in abundance,

nine to twelve inches in length, and

about 1-20th of an inch in diame- of this science within their reach, ter; coil it tightly round a bit of in a cheap and periodical form. stick, half an inch in diameter, Without pretending, however, to and then withdraw the stick: this draw up a whole system of Chewill bend the wire in a spiral form. mistry, though we shall be far Fix one end of it into a cork, which from merely copying what others fits the mouth of the jar or bottle in may have written on the subject, which the oxygen gas is contained, we shall under the present title so that it may hang down when in- present our readers, in a series of troduced into the bottle, and be articles, with a short and familiar kept firm by the cork, as in the view of Chemistry as a science. figure, E,: at the other end of the While the more advanced students wire attach a little charcoal, or will find in other parts of the work thread dipped in sulphur; light the information suited to their wants thread or the charcoal, and plunge and their taste, the papers under the wire quickly into the bottle; the present title are intended for it will instantly take fire, and those persons who are beginning throw out in all directions a num- the study. ber of brilliant sparks. The burn. Every body must have observed ing will appear in a dark room daz- that most of the substances around ling like the sun, and be, for those us are in a perpetual state of who have never witnessed such an change, and that many of these experiment, inconceivably splen- substances act upon and destroy did. If the wire be moved with a one another. Thus iron rusts, sudden jerk during the burning, and is, at length, unless protectso as to throw a melted globule ed from the air, quite wasted against the side of the glass, it will away and destroyed; and even melt its way through, or lodge it- the hardest wood moulds and self in the substance of the glass. decays, so that in a few years If instead of the bottle we use a it falls into dust and disappears bell-glass, completely open at one from our view. Thus also wood end, having a mouth to which a is instantly destroyed by a few cork is adapted at the other, and drops of vitriol; and the weakest which is filled in the manner above acid corrodes iron. Now, it is a described, but when full is re- settled principle, confirmed by moved, by a common saucer or many observations, that substances porcelain vessel being placed be- which, like the iron and the wood, neath the open end, then the glo- change their characteristics and bules of the metal falling through appearance, are not utterly lost or the water on to the saucer will fuse annihilated : the fact is, that they the glazing, and fix themselves so are converted into some other firmly that they cannot be sepa- things. The great agents in pro.. rated without scraping off the glaz- ducing these changes are water ing. It is hence necessary, when and air.* What we drink, and performing the experiment on a' what we breathe, therefore, while small scale, to cover the bottom of they are to us so apparently harmthe glass with sand to prevent the red hot globules from cracking it. * We may here observe, for the satis

faction of scientific readers, that we do CHEMISTRY AS A SCIENCE.

not include fire or caloric among these

active agents, because, as'must be known Art. I.

to them, there are among the best in

formed chemists differences of opinion, INTRODUCTION.

whether caloric be a separate substance, We shall not be far wrong. we or only a property of all matter. If the believe, in supposing that some of

former, we are wrong in omitting it; if

the latter, it would be as improper to inour readers may be totally unac

clude it, as to include wind, which all quainted with the science of Che philosophers kuow to be merely a movemistry, and that we shall meet ment synonymous with a property-of their views by putting an outline alls

less, so really beneficial, and even this supposition, which originated so necessary to our health and our many centuries ago with the ancient existence, are also the causes of Egyptians or Greeks, that it now those numerous changes which are forms a part of the popular belief constantly going on before our throughout Europe. The four eleeyes, and which are called decayments are frequently talked of, and and destruction. That the same were not long ago taught as the principles which warm every being bases of some sciences. It is the buinto life also bring on decay and siness of the Chemist to ascertain, destruction, is a fact which we shall if he can, what are the actual eleoften have occasion to advert to mentary bodies of which every one and illustrate : we only briefly als of the different objects of the globe Jude to it now in mentioning those are composed. Some are submitted numerous changes which are going to the action of fire, others to that on in every thing around. The of powerful solvents; some are whole surface of the globe, in fact, exposed to the action of water, the whole universe is perpetually and others are submitted to clecand periodically changing; but all tricity; and by all these, and vathese changes take place without rious other means, he endeavours the annihilation of any portion of to discover the different simmatter.

ple or elementary substances Some of these changes are ac. which undergo all these changes. companied by a perceptible mo- When, by all the means which tion; thus the waters of the ocean he can invent, he cannot change daily rise and fall: others are not or decompose one substance into so accompanied ; thus the state of two others, it is called a simple iron and wood is gradually alter- substance, or an element. In the ed, and nothing but the familiarity language of Chemistry, therefore, of the alterations keeps us from the term elements signifies those wondering at their cause. It is the bodies which the Chemist bas not object of mechanical philosophy to been able by his art to decompose. explain those alterations which are Unfortunately for the chemistry accompanied by perceptible mo- of the ancient world, and the theory tion; and it is the object of Che- of four elements, they have all mistry, by ascertaining the peculiar been decomposed by the art of properties of all bodies, to explain modern chemists. We shall herethose which are not. This is what after point out their composition; gives dignity and interest to the to do it now would draw us aside science. As long as Chemistry was from our principal subject. In a mere art, confined to producing a place of them, modern Chemists few results, of use only to a few are at present acquainted with, practical Chemists, it was of no according to some writers, fiftymore general interest, however use- seven, and according to others, fiftyful, than the art of house-building two different substances, which or shoe-making; but now, in ad- they have not yet been able to dition to its utility as an art, it change or decompose. It is, howendeavours to explain most of the ever, remarkable, that few or none alterations, unaccompanied by per- of these substances are ever found ceptible motion, which take place in a natural state, and they are in all the substances of the globe. nearly all of them the produce of

It has been already stated that the chemist's art. All the substances there is no annihilation; there and things of the globe, whether must be therefore some things animals, minerals, vegetables, or which are changed or altered. For- airs, (gases) which have hitherto merly it was supposed that all these been subjected to chemical exaalterations were effected in four mination, and there are perhaps elementary substances, viz. fire, very few unexamined, are found to earth, water, and air; and so consist of one or several of these powerful has been the influence of elementary bodies. They are liko the letters of the alphabet, with has a sharp acrid taste, which at which we put together all our last leaves an impression of sweetwords, and of them is this whole ness and a very peculiar smell, world of wonders composed. Nay, somewhat like that of garlic. When there is good reason to believe, as the arsenious acid is thrown on red the science of Chemistry, which is hot. coals, it evaporates in white yet in its infancy, advances to per- fumes, and this peculiar smell is fection, that this list of elementary then very perceptible. It is rather substances will be decreased. To more than three and a half times decompose them is one great ob- as heavy as water; and though it ject of the scientific Chemist's am- may be suspended in this fluid by bition; and we trust many of our agitation, it soon subsides if the readers, when they have acquired a agitation is put a stop to. Boiling knowledgo of the science, as it now water will dissolve a quantity about exists, will turn their attention to equal in weight to the fourteenth its improvement.

part of the water. Cold water only There are two modes in which dissolves about one tenth part as a knowledge of these elementary much as boiling water. Other ausubstances may be conveyed to the thorities say it is soluble in thirstudent of chemistry. The first is, teen times its weight of boiling, to show him, by going through an and cighty times its weight of cold analysis of every known substance, water. Water in which arsenious of what elements it consists; the acid has been dissolved, reddens other is simply to bring these ele- litmus paper, as well as the most mients before him in succession. sensible of the blue vegetable coThe former would, in fact, be mak lours, but it turns the syrup of ing him do what others have done violets green. If lime water be for him; the other is applying to his added in sufficient quantity to the immediate instruction the discove- solution of arsenious acid, a fine ries and knowledge of others. We white precipitate, which is arsenite prefer the latter as more simple, of lime, is perceptible. Sulphuand shall, in our next Article, pro- retted hydrogen gas and hydrosulceed to describe the substances phuretted water precipitate a golwhich, never having been yet de. den yellow sulphuret of arsenic: composed, are considered as ele- and by this test a portion of arsenimentary or simple substances. ous acid in water, not greater than

a hundred thousandth part of the TESTS FOR ARSENIC. . whole, may be detected. If this

The use which is sometiires yellow sulphuret be dried on a filmade of this substance to destroy ter, and heated in a glass tube life, makes a knowledge of the with a bit of caustic potash, it will, means of detecting its presence of in a few minutes, be decomposed : great practical utility. The sub- sulphuret of potash will remain at stance sold under the name of ar- the bottom, and metallic arsenic, senic in the shops, is called arseni- of a bright steel lustre, which subous acid, or white oxide of arsenic, by limes, will be found coating the chemists: the former name being, sides of the tube. Nitrate of silver at present, more in use than the is decomposed by arsenious acid, latter. The term arsenic is applied and an arsenite of silver, of a very by chemists to a metallic substance peculiar yellow colour, is precipiobtained from arsenious acid, and tated. To prevent this precipitate which they consider to be a dis being dissolved by nitric acid, tinct metal. With its properties which is very often present, a small we have now nothing to do, as this quantity of ammonia is added ; paper is to be devoted to the viru. and even this, if too much is added, lent poison, called arsenic in the is also likely to re-dissolve the sil. shops, and arsenious acid by the ver precipitate. chemists.

To ascertain if arsenious acid It is a white brittle substance, has been administered, the first

« 이전계속 »