Imágenes de páginas

fingers of a dead man's hand, and her death, under a total deprivation of meneyes rested on the blanched cheek- tal faculty. * * Amelia awoke once bones and whitened skull of a human more from a state of lethargic stupeskeleton ! Yes, it was Henry. At a faction to sense and reason. She gave short distance was found a bottle, the above brief sketch, clutched her which had contained laudanum, enclos- hands, closed her eyes with a shudder, ed in a sheet of paper, written in a laid her head back upon her pillow, wild, incoherent manner, leaving no and her pure spirit returned to Him doubt as to the manner or cause of his who gave it.

(Sel. Mag.)

INTRODUCTION---BOMOGENEOUS AND HETEROGENEOUS ATTRACTION-CALORIC. THERE is perhaps no branch of This it is which under the name of

science which has improved so gravitation attracts all bodies to the rapidly within the last thirty years as earth. The chief connexion it has with that of Chemistry. Before that time it chemistry is, that it may be considered wanted regular classification, and was as being the primary cause of crystalentirely veiled from the eyes of all but lization ; a subject upon which our the professed philosopher, owing to the narrow limits and its present uncertainConfusion of its nomenclature. But ty must prevent our enlarging. We now it presents to all an interesting field will therefore pass on to heterogeneous of enquiry, which will amply repay the or chemical attraction. This from casual as well as the unintermitting la- some property unknown to man, causes bourer. By the help of this science, particles of different natures to unite in he may examine and admire the works various manners. If into a glass conof the great Creator of the universe, as taining a piece of copper, some nitric well in the objects which are constantly acid * be poured, the acid will immedibefore him, as in the grander operations ately unite with the copper, and form a of nature. To give a brief outline of new compound, which does not partake this interesting branch of knowledge of the properties of its elements, but will be the object of this and the follow- presents a distinct character. This is ing papers.

the first thing we should observe in the The investigation of the properties unions caused by chemical attraction; and mutual action of elementary parts that, for the most part, the compound of bodies, and all changes in the con- formed differs entirely from both its elstitution of matter, whether effected by ements; whereas, in the unions caused heat, mixture, or any other means, may by homogeneous attraction, no change be considered as the peculiar province in the nature of the matter acted upon of chemistry. It must therefore be one can take place. Thus, in the case beof the most diffuse subjects upon which fore us the acidity of the nitric acid is we can enter; and to treat it with reg- gone, and a body remains which parularity will be indispensably necessary. takes of none of its powers. The Let us first then take a view of the chemical nature of the body is not the powers and properties of matter con- only thing that experiences a change. Dected with chemical changes. These Frequently the colour and solidity of may be viewed under the heads of the body are equally affected. In the 1. HOMOGENEOUS ATTRACTION.

case before us, the resulting compound
IL. HETEROGENEOUS ATTRACTION. is of a beautiful blue colour, which was

* Nitric acid will be treated of in the course of Homogeneous attraction, or the attrac

these papers. For the sake of preserving regularity po more than its name can now be mentioned. It nray be obtained at the chemist's, by any persons

desirous of trying the experiment, but great care union of particles of the same nature. should be taken in using ii, as it is a very corrosive 6

s clothes. ATHENEUM VOL. 1. new scries.

fuid, and rapidly desam


seen in neither of the original bodies. matters. A single column of this sort Solids are changed by it into aëriform is here introduced as a specimen. shapes, as when gunpowder is inflamed.

SULPHURIC ACID. * But we may also observe that, during the process of this union, great



MAGNESIA. commotion appears in the bodies acted

AMMONIA. upon. This is the case in the instance

SODA. to which we have already alluded. A. From this table we should deduce great deal of air is extricated during that sulphuric acid had a greater affinity the decomposition of the copper. In to baryta than to strontia, to strontia many unions, however, the immediate than to potassa, to potassa than to soda, effect is much greater. If sulphuric ac- and so on; and, consequently, that baid* be added to water, in the proportion ryta would decompose any compound of four pounds of the latter, so much of sulphuric acid formed with those baheat will be produced in the mixture as ses enumerated after it. There are to raise the thermometer to 300° Far- two classes of decomposition, simple enheit.

and double. In the simple, one body We shsll also find that, after a time, separates a second from its combinathis commotion will cease : from which tion with a third. In the double, two we may learn that nitric acid and cop- new compounds are formed; as when per will only unite in certain propor- nitrate of baryta* and sulphate of soda tions.

are mixed, the nitric acid of the former Another very important fact in the compound quits its form, and enters system of chemical attraction is, that into a new compound with the soda ; different bodies are possessed of differ- while the sulphuric acid quits the soda, ent attractive powers. If into the so- and enters into a new compound with lution (chemically termed nitrate of the baryta : so that two new comcopper) which we obtained in the for- pounds, nitrate of soda and sulphate of mer experiment, a piece of iron be im- baryta, are formed. It is evident from mersed, you will perceive that it will be what has been said, that there are some immediately covered with a thin coat. laws which govern the union of particles ing of copper. The cause of this is, of different natures. Concerning these

to the iron, than to the copper it holds the particles to unite, many conjectures in solution ; that, consequently, it quits have been made, but nothing certain the copper and forms a new compound has been discovered. Some suppose with the iron; the copper being thus that all particles of matter are endued relinquished is precipitated, and forms with one of the two electricities, and that thin coating which you may ob- that these subtle fluids are always tendserve on the surface of the iron. Upon ing to unite. But as we do not intend this principle depends the power of to enter upon the more abstruse points cliemically decomposing bodies, i.e. re- of chemistry, but merely to take a gen,ducing them to their original matters. eral and popular view of the science, Here the copper is first dissolved by we will pass on to the next general the acid, and then the compound thus power alluded to, heat or caloric. formed is decomposed by the interven. There are many doubts entertained tion of the iron, and the copper restored as to the nature of this agent. It is in its former state. On this principle however generally supposed to be a it is that chemical tables have been fluid pervading, more or less, all matformed, by which at one view the ter, and has been divided into chemist may be informed of the various I. FREE Caloric. powers of attraction between different II. Specific Heat, or COMBINED CALORIC.

* Further mention of sulphuric acid must be post. poned for the same reason as that of nitric. It may be obtained at the chemist's. Greater care should be taken of this than the nitric, as it destroys not only clothes, &c. but also animal fibre, and consequently would cause painful wound:.

* Although the reader may not yet know what these drugs are, he may still make the experiments alluded to. It would be quite impossible to preserve any regularity of design, if we stopped to explain the nature of each drug alluded to by way of example. They will all of them be explained hereafter.

The name caloric has been proposed are the worse conductors, down to woolin the new nomenclature as a substi- len cloth, flannel, and down, which is tute for heat, which has by common use one of the lightest bodies and at the been applied merely to the sensation of same time one of the worst conductors heat. One of the great characteristics The reason of this may probably be, of caloric is, that it always tends to an that in the dense substances there is equilibrium. It may be supposed that much less air, which scarcely conducts there are rays of caloric flowing in all caloric at all. On this principle of the conceivable directions from all bodies. different conducting powers of bodies, But when any body is below the tem- depends the mode of clothing ourselves. perature of those around it, the rays of Flannel and woollen dresses being very caloric flowing from it are not equal in bad conductors of caloric, prevent, number to those which it has a capacity when the temperature of the atmos

perature is gradually heated to the same the escape of the animal heat from warmth with the objects around it. them, and thus keep us warm in the When bodies are once raised to the winter season. The same dress would same temperature with the atmosphere keep us cool when the atmosphere was around them, they radiate and absorb warmer than our body, as it would caloric in equal quantities, so that they prevent its penetrating to our frame. If preserve their equilibrium. Cold is merely you lay your hand on a piece of marble, a negative subject, implying the absence on the wood of the table, and on the of heat. Thus, when we lay our hand carpet of the room, they will all appear upon a marble slab, the feeling of cold to you to be of different temperatures; which we experience, is merely the cal- the marble coldest, the wood medium, oric flowing from our hand into the the carpet warmest, and yet the thermarble, and endeavouring to raise the mometer would inform you that they marble to the same temperature, are really of the same temperature,

We have already observed that calo- The reason of this is, that the marble ric is proceeding in different rays from being the best conductor of caloric of all bodies. This is called the radia- the three,(as they are ail of a temperation of caloric. Different bodies have ture below that of your hand, though of different radiating powers. This has the same with the atmosphere,) absorbs been clearly proved by the experiments from you the caloric you possess more of Mr. Leslie. All heat which is per- rapidly than the others; and though it ceptible to the senses may be consider- really makes you no colder than the ed as free calorie..

others would in the end, vet as it proBesides the power of radiation, calor- duces the same effect in a shorter time, ic may be reflected, subject to the same the change is more sudden, and conselays as those which govern optical re- quently the sensation of cold (which flection.—Another very important pow. we must always remember is merely er of caloric is, its expanding all bodies, the abstraction of caloric) is much and thus acting in direct opposition to greater. The reverse of this would the attraction of cohesion. It effects be seen, from the same cause, were we this by introducing its particles between to put three pieces of ice on the various the particles of the body upon which it bodies enumerated. In this case, that acts. The power of bodies to bear in on the marble would first be melted, this way the introduction of caloric be- that on the wood next, and that on the tween their particles, is called their con- carpet last, because, here the conductducting power. All bodies have more ing power would act the other way, and or less the power of conducting caloric, induce the marble to part with its exbut some possess it in a much stronger cess of caloric to the ice more readily degree than others. Generally the than the wood or the carpet could do. denser bodies, such as metals, &c. are And here we must admire and adore the best conductors of caloric. Porous the gracious dispensations of a Being substances, such as wood, cork, &c. who has stooped to adapt the various

coverings of his creatures to the circum- worst conductor of caloric known to stances in which they are placed. Who us) the breast of aquatic birds, which has provided those most exposed to cold is the part most exposed to the action with furs or with plumage, and who of the water.


(Lit. Gaz.)

MTHE mingled character of Cowper even within the same paragraph, of the

is finely displayed in these Let- adventitious, or perhaps we should say, ters, and they are full of anecdote and the habitual, and the natural. The remark upon the literature of the pre- change from one to the other, at the ceding generation. From grave to last clause, is striking. gay the transitions are charming ; butu Though much obliged to you for the we will offer no farther comment on favour of your last, and ready enough to volumes which we can illustrate in so acknowledge the debt, the present, however, gratifying a way by the following al- is not a day in which I should have chosen most unselected extracts :

to pay it. A dejection of mind, which per" To Joseph Hill, Esq. disqualifies me for writing a business I

would always perform in good spirits, be“ Jan. 21, 1769.

cause melancholy is catching, especially « DEAR JOE,--I rejoice with you in your where there is mnch sympathy to assist the recovery, and that you have escaped from contacion. But ce the hands of one from whose bands you understand are abont to pay their respects will not always escape. Death is either the to you, have advertised for an agreeable most formidable, or the most comfortable

companion, and I find myself obliged to thing, we have in prospect, on this side of embrace the opportunity of going to town eternity. To be brought near to him, and with them in that capacity

with them in that capacity." to discern neither of these features in his

..." I remember (the last thing I mean face, would argue a degree of insensibility, of which I will not suspect my friend, whom

to remember npon this occasion) that Sam I know to be a thinking man. You have

Cox, the counsel, walking by the sea-side, been brought down to the sides of the

as if absorbed in deep contemplation, was grave, and you have been raised again by

questioned about what he was musing on. Him who has the keys of the invisible

He replied, I was wondering that such an world; who opens, and none can shut,

almost infinite and unwieldy element should who shuts, and none can open. I do not

produce a spral"... forget to return thanks to Him on your be. The following is very pleasant and half, and to pray that your life, which He has spared, may be devoted to his service,

natural, and the style of it is the per• Behold! I stand at the door and knock, fection of easy simplicity. The occais the word of Him, on whom both onr mor. sion was that of having just converted tal and immortal life depend, and blessed a little summer-house in his garden inbe his name; it is the word of one who to a writing room

to a writing-room. wounds only that He may heal, and who waits to be gracious. The language of "It is an observation that naturally ocevery such dispensation is, ' Prepare to curs upon the occasion, and which many meet thy God.' It speaks with the voice other occasions furnish an opportunity to of mercy and goodness, for without such make, that people long for what they have notices, whatever preparation we might not, and overlook the good in their possesmake for other events, we should make sion. This is so true in the present in. none for this. My dear friend, I desire and stance, that for years past I should have pray, that when this last enemy shall come thought myself happy to enjoy a retire. to execute an unlimited commission upon ment even less flattering to my patural ns, we may be found ready, being estab. taste than this in which I am now writing ; lished and rooted in a well-grounded faith and have often looked wistfully at a snug in His name, who conquered and triumph. cottage, which, on account of its situation ed over him upon his Cross.

at a distance from noise and disagreeable Yours ever,


objects, seemed to promise me all I could We extract the following short pas. wish or expect, so far as happiness may be sage for the purpose of pointing out the this comfortable nook, which affords me all

said to be local; never once adverting to singular mixture which it presents, that could be found in the most sequestered

hermitage, with the advantage of having

it were not a vicious one; but however car. all those accommodations near at hand

nestly invited, it is coy, and keeps at a diswhich no bermitage could possibly afford

tance. Yet with all this distressing gloom me. People imagine they should be happy

upon my mind, I experience, as you do, in circumstances which they would find in

the slipperiness of the present hour, and sopportably borthensome in less than a the rapidity with which time escapes me. week. A man that has been clotbed in tine Everything around us, and every thing linen, and fared sumptuously every day, that befalls us, constitutes a variety, which, envies the peasant under a thatched hovel :

whether agreeable or otherwise, has stili who, in return, envies him as much his pal.

a thievisb propensity, and steals from us ace and his pleasure-ground. Could they days, months, and years, with such unparchange situations, the fine gentleman would alleled address, that even while we say they find his ceilings were too low, and that his are here, they are gone. From infancy to casements admitted too much wind; that manhood is rather a tedious period, chiefly, he had no cellar for his wine, and no wine I suppose, because at that time we act unto put in his cellar. These, with a thou. der the control of others, and are not sufsand other mortifyiog deficiencies, would fered to have a will of our own. But shatter his romantic project into innumera. thence downward into the vale of years, is ble fragments in a moment. The clown, at such a declivity, that we have just an op. the same time, would find the accession of portunity to reflect up..a the steepness of it, so much unwieldy treasure an incumbrance and then find ourselves at the bottom." quite incompatible with an hour's ease, His choice would be pozzled by variety.

The passage which follows we should He would driok to excess, because he willingly have passed over, if we could would foresee no end to his abundance; bave persuaded ourselves that it really aod he woold eat himself sick for the same belonged to Cowper. We can only reason. He would bave no idea of any other happiness than sensual gratification :

trust ourselves to say that it is addresswould make himself a beast, and die of his ed to the Rev. Mr. Newton, the poet's good fortape. The rich gentleman had, friend and religious Mentor-a person perhaps, or might have had, if he pleased, who not long afterwards " improved at the shortest notice, just such a recess as this; but if he bad it, he overlooked it, or,

the occasion" of Handel's celebrated if he had it not, forgot that he might com.

Commemoration,by preaching a sermon mand it whenever he would. The rustic, on the prosanation of that ceremony ! tno, was actually in possession of some

“He seems, together with others of our blessings, which he was a fool to relinquish,

isa, acquaintance, to have suffered considerably but which be could neither see nor feel, be in his spiritual character by his attachment cause he had the daily and constant use of tomusic. The lawfulness of it. when used thern ; such as good health, bodily strength, with moderation, and in its proper place, is a bead aod a heart that never ached, and

unquestionable ; but I believe that wine ittemperance, to the practice of which he was

sell, though a man be guilty of habitual bound by necessity, that, humanely speak

intoxication, does not more debauch and ing, was a pledge and a security for the hefool the natural understanding, than mucontiquance of them all.

sic, always music, inusic in season and out "Thus I have sent you a school-boy's of season, weakens and destroys the spiri. theme." • •

tual discernment. If it is not used with The following is another singular an unfeigned reference to the worship of compound of gloom and buniour. It God, and with a design to assist the soul would be worth extracting, if it were

in the performance of it, which cannot be

the case when it is the only occupation, it only for the capital simile about the ri- degenerates into a sensual delight, and be. ot-act.

comes a most powerful advocate for the *I do not at all doubt the truth of what admission of other pleasures, grosser peryou say, when you complain of that crowd haps in degree, but in their kind the of trifling thoughts that pesters you without same." ceasing ; but then you always have a seri.

We meet with several passages in

W our thought standing at the door of your imagination, like a justice of peace, with the these volumes in which Cowper roundriol-act in bis haod, ready to read it, and ly asserts that all the light and humourdisperse the mob. Here lies the difference ous passages in his poetry are mere between you and me. My thoughts are tricks invented purely to inveigle the clad in a sober livery, for the most part as grare as that of a bishop's servants. They

et reader into listening to something more

reader into listening to tere too upon spiritual sabjects, but the serious and useful. To this, as before, tallest fellow and the loudest amongst we shall only venture to say, that the them all, is he who is continually crying passages in question occur in letters adwith a loud voice, Actum est de te, periisli. Yoo wish for more attention, I for less. Dis dressed to Mr. Newton. Here are sipation itself would be welcome to me, so two of them:

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