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And yet I grieve not for the time

circulation through the minute vessels of young delight, though quickly gone,

over the whole body, giving stimulus Will serve, as many a bill I climb, For memory to dwell upon.

to the operations of the animal econoAs when the sun tho set will leave my, and a beautiful provision for the A beauty which the clouds receive, maintenance of a uniform animal temSo childhood on the growing boy

perature. Reflects its innocence and joy.

The blood, then, in passing through I've chas'd the painted butterfly

the lungs, is freed of two noxious O'er many a field and woodland far, principles, namely, carbon and hydroAnd never yet have breath'd a sigh, Jn scenes where want and sorrow are.

gen; and indeed the extreme great I've watch'd the streamlet's shallow tide,

quantity of the former of these is And slept for hours upon its side:

astonishing, amounting to do less The green sward was a happy seat,

than 11 ounces in the 24 hours. A The linnets' song was always sweet. small quantity of oxygen is absorbed ; The future is a world unknown

and the arterial blood becomes loaded The past, a hallow'd track of beauty, with caloric. O'er which the hand of Time bas thrown The support which atmospberic air

No slavish care, no toilsome duty. administers to combustion, entirely Yet, if in my young hemisphere A cloud or darkling spot appear,

depends upon the presence of Oxygen I'll wait 'till it is past, and then

Gas ; for combustion will never take Smile on the sunny beams again.

place without this gas be present. And when I think, I'll think of bliss,

The atmospheric air is decomposed ; My youthful thoughts from sadness wean

the conbustible body absorbs its oxying;

gen; while its other constituent parts Let Fancy rest, on that which is

are set at liberty. Air is invisible, Like Hope upon her anchor leaning. colourless, and elastic, capable of inAnd when the shadows round me close, I'll lay this body to repose;

definite expansion and compression. A plant whose bloom to earth is given,

Elasticity is one of the most obvious Whose fruit will be reserv'd for heaven. properties of air, and it is, perhaps,

G. M. the one upon which philosophers have

made the greatest number of experi

ments. We are acquainted with a CHEMICAL ESSAYS.-ESSAY IV. great number of facts, illustrative of

the air contracting its volume, and re( Continued from col. 516.)

covering the state from whence it was

displaced, upon the entire removal of In my brief essay on Oxygen, I ob- the causes by which it was compressserved that the blood is converted into ed. If a bladder, containing a small a red oxyde, by the oxygen of the quantity of air, be tied up with a atmosphere acting upon the iron con- string fast round its neck, and placed tained in the blood ; but I should have under the receiver of an air pump, it mentioned also, that there are many will gradually swell as the receiver is modern chemists who deny the exist- exhausted, till it becomes quite full, ence of iron in the globules of the which is owing to the elasticity of the blood; notwithstanding which, I am small quantity of air contained in the still of opinion that the globules of the bladder, dilating and expanding itself blood do contain a small quantity on the removal of the atmospheric of iron; the traces of which I have pressure. The same expansion takes always found sufficiently distinct to place if we carry the bladder to the satisfy myself as to the reality of its top of a very high mountain. So likeexistence. The oxygen of the atmo-wise bubbles of air rising from the sphere cannot enter into chemical bottom of a glass of water, gradually combination with the carbon thrown dilate as they approach towards its off by the blood, to constitute Carbo- surface, owing to the gradual diminupic Acid Gas, withou a portion of tion of the pressure of the water. It is caloric being evolved ; now this calo- also owing to the elasticity of the air, ric is seized by the arterial blood, and that thin glass globes filled with air when it passes on to the veins, its ca- burst asupder upon the exhaustion pacity for caloric is diminished as of the receiver of an air pump. much as it had been increased in the The generality of fishes are furnishlungs; the caloric, therefore, is gra- ed with an air bladder; which is dually evolved in the course of the placed very near to the backbone; 605

Chemical Essays.


and this they have the power of con- | the year 1564. Although Galileo was tracting and dilating at pleasure. By well acquainted with the weight or contracting this bladder, and thereby gravity of air as a body, yet it is to his condensing the air within it, they can, ingenious pupil, Torricelli, that we with very little exertion, render them- | are indebted for the discovery, that it selves specifically heavier than water, is the weight and pressure of the atand enable themselves to sink to the mosphere wbich keeps water raised in bottom. On dissection of the bladder pumps, and mercury raised in baroof fishes, we find that it has an ex- metrical tubes, and that a column of tremely strong muscular coat, by air, of the whole height of our atmomeans of which the animal has the sphere, is equal to a column of water power of contracting and dilating its of equal base, 34 or 35 feet high, and bladder to a smaller or greater size as a column of mercury of an equal base, best suits its convenience; and there- 30 inches high; hence water never by of swimming in any depth of water, ascends in common pumps higher than or rising to the surface with the great- 35 feet, or mercury in barometrical est facility. It is upon this property tubes higher than 31 inches. of the air of which we have been If the student (for the use of whom speaking, and upon which we shall these essays have been principally make some further observations, that written) is in possession of an airthe forcing pump and air-gun are pump, he will derive considerable constructed ; and it is also by this advantage from the performance of the property that air is chiefly distin- following experiment. Take a comguished from other fluids. It is the mon glass cylinder, or receiver, open generally received opinion, that the at both ends, and place it upon the atmospheric air owes its elasticity plate of the air pump. The experientirely to the caloric it contains. mentalist is now to cover the upper

As a proof of the great elasticity of most open end of the cylinder with the air, it will be sufficient to observe, the palm of his hand, and exhaust the that Mr. Boyle succeeded in dilating cylinder of its air. The pressure being it, till it occupied nearly 14,000 times now entirely taken off from under the its ordinary space, without the appli- hand, he will immediately become cation of heat, and by only removing sensible of an almost insupportable the pressure by means of an air-pump. weight, which presses down the hand The elasticity of the air is diminished to the receiver, with a force sufficient by cold, and greatly increased by the to cause considerable pain, and inapplication of heat, as may be shewn deed to break the hand, if it is not by holding a bladder, containing a soon removed from its uneasy situavery small quantity of air, to the fire; tion, which can only be done by the upon the rarefaction of the inclosed re-admission of air into the receiair, it will gradually expand till it ver. appears quite plump, and will return Air can be even weighed with as to its former flaccid state, when re- much accuracy as any other substance. duced to its former temperature. It | The difference of weight between a is upon this principle that the struc- vessel filled with air, and another vesture and use of the thermometer de- sel exhausted of its air, may be reapends.

dily ascertained, and this difference The next property of the air which will be proportionally more sensible, I shall notice, is its fluidity; a pro- if the vessel be filled with condensed perty which it never loses; whether air. A quart measure of atmospheric under the strongest pressure, or ex- air taken near the surface of the earth, posed to the greatest artificial cold we weighs about 17 grains. The specific are able to produce. In all bodies in gravity of atmospheric air, as deterwhich it lodges, or is kept in close- mined by Sir George Shuckburgh, is stopped vessels for a great number of 0.0012, the barometer being at 30 years, it still remains in a state of inches, and the thermometer between permanent fluidity.

50 and 60 deg. It is, therefore, 816 The next obvious property of the times lighter than water. air is, its weight or gravity :-a pro

I have said that the whole pressure perty which was discovered by the of the atmosphere is equal to a column immortal Galileo, a celebrated astro- of mercury of an equal base, and 30 nomer and mathematician, born in inches high, and as a column of mer


cury of this height, and an inch tion, as shewn by the following Tasquare, is found to weigh 15 pounds, ble. it follows that the pressure of the at

Height in Miles above Number of mosphere amounts to 15 pounds on

the surface of the earth.

times rarer. 7

4 every square inch of the earth's surface; consequently, the pressure on

16 21

64 every square foot of surface, amounts to 2160 pounds. If we reckon the



35 external surface of a man's body to be

1024 about 15 square feet, and the ordi



49 nary weight of the atmosphere 2160


56 pounds on every square foot, he will

65536 sustain a weight amounting to nearly


262144 14} tons. The weight of the atmo


1048576 sphere, however, is not always the

4194304 same, and indeed the difference in its


16777216 weight from the natural changes in


67108864 the state of the air is often very consi



105 derable, and it would be no difficult

1073741824 task to shew that the difference in the



119 weight of the atmosphere on the sur

17179869184 face of a man's body, supposing it, as



133 before, to be equal to 15 square feet,


140 1099511627776 is nearly 1} ton. We have, there

For some of the most accurate exfore, no reason to wonder that invalids do so powerfully experience the periments relative to the aqueous vavariation of the additional pressure of pour contained in the atmosphere, I the atmosphere ; but we have reason

refer the reader to the writings of to wonder that so great an additional that excellent chemist, Mr. Dalton, of pressure should be borne at all without Manchester. I am well aware of ihe

truth of the ancient maxim, crusbing the frame of our bodies to pieces. But the fact is simply this, book is a great evil,” and I have enthe interior cavities of our bodies deavoured to improve upon this maxalways contain some elastic fluids, the im, of the importance of which as a re-action of which is sufficient to ba- modern writer, I am so well satisfied; lance the weight of the external atmo- but I have already extended this sphere.

paper to a greater length than I had Dr. Vince has given the pressure originally intended, for which reason or weight of this ambient fluid on

I am obliged to suppress the latter the whole surface of the earth part of it, containing observations on at 77,670,297,973,563,429 tons.

the existence of those bodies, which,

Dr. Cotes reckons the weight equivalent although they cannot be considered as to a globe of lead 60 miles in dia- constituent parts of the atmosphere, meter. And Dr. Thompson gives shall therefore conclude with noticing

have been occasionally found in it. Í 11,911,163,227,258,181,818 pounds, avoirdupois, for the whole weight the following principal errors of the of the atmosphere. As air is an press, in my preceding essays, which elastic fluid, and its density being the candid and liberal reader will always proportional to the weight by please to correct with a pen, the one which it is compressed, it follows that marked with an asterisk materially

affects the sense. its density diminishes according to its distance from the surface of the earth; Col. *26, line 45, for atmospheric air,

read water. Col. 28, line 43, for consequently, the air on the top of very high buildings is considerably

oxymuriate, read oxymuriatic. Col. rarer than that at the surface of the

227, line 52, for sulphurat, read earth, which is compressed by the whole

sulphuret. Col. 228, lines 45 and weight of the incumbent atmosphere.

47, for Kerwan, read Kirwan. Col. Philosophers have demonstrated,

228, line 49, for of, read by. Col. that if the altitudes in the air do 347, line 39, for were, read are. Col. continually increase in arithmetical 347, line 55, for was, read is.

JOHN NUTTALL. proportion, the rarity of the air will

Handsworth Woodhouse, near Sheffield, be in continued geometrical propor

15th April, 1822.

A great 609

Dialogue between Mahomel and the Duke of Guise.




DIALOGUE BETWEEN MAHOMET & THE is also unconceivable. But this was DUKE OF GUISE, IN THE SHADES. not your fault, the schoolmen should

have mended it. Mah.-Come, let us sit down here, Duke.--Abundance of them have and laugh a little together at all those tried to do it. tricks you and I have put upon the Mah.-But to no purpose ; 'tis such world.

a patched business, between the suDuke.— With all my heart: What perstitions of old Rome and new better use could we bave made of it? | Rome, blended together, that the Is mankind fit for any thing but to be wise at last were ashamed to wear it, cozened?

and did as good as throw it quite off, Mah.Yet you must confess that by what they called a Reformation. my way is the more noble, and bad Duke.-Very well, Sir; but is any something of the sublime in it: you thing so ridiculous as your lies? did your business by nothing but mere Mah.Yes, your legends. But cringing.

shall I confess a truth which will make Duke. You are mistaken : there amends for all my lies? goes more to popularity than that Duke. That will be something difcomes to; and yet the cringing you ficult. speak of, when 'tis of the mind, is no Mah. -Why; I began to believe such easy matter.

them myself, at last. Mah. Not to so lofty a one Duke.---Oh, ridiculous ! yours; perhaps low stooping makes a Mah.I was so very fortunate, that tall man's back ache.

I fancied myself a kind of favourite Duke.-You are merry, Sir; there- of heaven ; and if I bad been put to fore I suppose you will not be loth to it, 'tis not impossible but I might have confess some of your noble tricks, as died a martyr for a religion of my you call them.

own invention. Mah.--On condition you tell yours.

Duke.---That is more incredible Duke.--Agreed, and pray begin : than any thing in your whole AlcoMine was but lay-dissembling, which ought to give place to divine hypo- Mah.Then, for all your populacrisy.

rity, you are not much skilled in manMah.--You have heard of my pi- kind. Why, we are all of us but geon, I warrant.

overgrown children, afraid in the dark Duke.-Yes, and of your owls too: of our own scarecrows; and as fond Could such a gross thing pass among too sometimes of the babies we ourthem?

selves trick up. Mah. As easily as a creed: nay, Duke.- Is it possible? at last I might have spared my pains Mah.--Yes, to flatter a man into of teaching the pretty bird ; for the any thing. Alexander himself, the rabble would have fancied her at my pupil of Aristotle, and the very top of ear, though she had been all the all humanity, did at last believe that while fluttering in their faces.

Jupiter was his father; and by his Duke.— Nay, though she had been saying that sleep bad best convinced picking out their eyes, for I must him of his being mortal, 'tis plain he acknowledge you the best of all the sometimes doubted it. bigot-makers that ever I read of. My Duke.—Like enough. And did your superstitious coxcombs never reached instruments, Sergius the monk, and either the devotion, or morality, of the rest of them, believe themselves yours.

too? Mah.That is, because I laid a Mah.--Religious sort of men, you better bait than any in your legends. know, outdo all others in flattery; and Is not that more desirable, than pass- I having set them up for my ends, ing through fames of purgatory, to they sanctified me for theirs, till we only spiritual imaginary pleasures? almost acted ourselves into a real

Duke. But sure, our joys unspeak- veneration for one another. But tell able are above even yours, which in- me now a little of your pranks, for deed, in decency, ought to have been you played them I hear to some purunspeakable too.

pose. Mah.-Have a care of that; 'twill Duke.- I had so, if the business at never do. Whatever is unspeakable Blois had not prevented me.





Mah. But you had a fine time of it worth a thousand of your school-distill then.

tinctions, which are but slight cobDuke.-Very far from it. Rowing webs spun out of case and idleness. in the galleys is nothing to the toil of Being witty out of season, is one popularity: but ambition is rebutted sort of folly. with nothing.

A HUMOURIST. Mah.—Why, pray where was all this trouble?

Duke.—First, I never said one word I thought, and passed my life in gaining surly people's affections, whom all the while I contemned for

“ The visions of my head troubled me." being deceived so grossly.

DAN. vii. 15. Mah.-But yet you had the plea- So said Daniel, a long time past: I sure of advancing your friends every may truly repeat his declaration, and day.

shall think it a favourable circumDuke.-As seldom as possible, and stance if they do not trouble the reader I did it always unwillingly.

also. Mah.-How then came they to fol- In my dream, I found myself upon low you so much, and almost adore a lofty hill, whose summit was enveyou as you went along the streets? loped in clouds, and every thing upon

Duke. Now 'tis you are catched; it had a most extravagant appearance. I am glad to find you so much out at Every person seemed most fantastithe knowledge of mankind.

cally dressed and whimsically emMah. Why pray, what is the mat- ployed; some were bottling up the ter?

air in phials, to discover what it was Duke.-Obliging men is not the made of; some were making scales way to win them.

to weigh the planets in ; some finding Mah.-Methinks it should be so. out a new method of guiding the

Duke.—Quite contrary: every man tides ; and some a new way for forgI advanced, thinking his business ing thunder-bolts ; some were busy in done, never minded me afterwards; mending the Bible by their reason, so there I lost a friend, and made a and some were accommodating relihundred enemies out of envy to gion to their passions and failings; bim.

some decked themselves in cobwebs; Mah.--But yet you ordered your some strutted along in ribbons ; some business so as to have a great many making themselves wings of wax; and friends, and few enemies, except the some building pyramids of snow. Huguenots.

“* Bless me,' said I, rubbing my Duke.-True, but it was only by eyes, “where am I got to? A deseeming kind to every body, and all cent-looking man, who had the apthe while caring for nobody. I used pearance of an honest preacher, and them just like a herd of beasts, as happened to be near me, replied, indeed they are; increased their num- This, Sir, is the Hill of Conceit; ber all the ways I could, valued them and these are the self-made philosoaccording to their use, but loved none. phers and doctors of the place; take Would you have had me fond of a care you are not infected with their black ox or a red cow ?

madness; make baste to yonder valMah. For aught I see, never man ley, or you will soon catch the pestiwas beloved so much, or deserved it lence of the place.' Thanking him

for his advice, and inquiring his Duke.--Thank you for your compli- name, I turned my steps downward. ment; and not to be ungrateful, I be- “I am Plain Truth,” said he ; “mind lieve never any religion has been how you proceed. This caution was spread or practised so much as yours, necessary, for I was soon surrounded and yet without the least shadow of by a host of projectors, and proposers, wit or learning

and authors, and such like persons, Mah. That is the reason it took so who solicited my subscription and much. Whoever aims at mankind patronage to their different schemes must not shoot high: fine nets may and proposals ; but I forced myself catch birds, but they never hold from them and made my escape, at beasts. Mine were coarse and strong, the expense of a few shillings, over

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so little.

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