-.,..

4‘ Ofriend! wilt thou forget

' , bani-u. *

[Fort can Comm“. Human]

1*" ' r THE COUNTRY SURGEON;

Luckiess is he whom hard fates urge on To practise as a Country Surgeon ;

To ride, regardless of all weather, Through frost, and snow, and had together. At every quarter of the compass,

A surly patient makes a rumpus,

Because he is not attended first,

(For each man thinks his case the worst ;) And oft at two points diametric,

Called to a business obstetrick, There lies a man with broken limb 5

A lady here with nervous whim,

Who, at the acme of her fever,

Calls him a'savage if he leave her,

For days and nights, as oft the case is, To live on herring and potatoes 3

And thatjob over, happy be,

if he squeeze out a guinea fee. .

Then home he goes, both sick and tired, Considered as a servant hired, _

\Vhen, like culprit ’scaped fromjail,

Ilc sits him down to hasty meal;

He sits! when lo! a atient comes,

\VIth lotton tooth an utrid gums !

He quickly takes his own tools,

Fixes the claw, and tugls and pulls: _ His dinner’s cpld—his ands this mess in— All for a shilling—or—a litermng.’

Now come- the night; With totl opprest, He socks his bed, in hope of rest '.

Vain hope l—hc scarcehas raised a snore, \Vhen sounds the knocker at his door;

A farmer’s wife, at ten miles’ distance, Groaning, calls out for his assistance. Fictiing and fuming in tho dark,

He from the ashes blows a s ark,

And as be, yawning, throws is clothes on,

P

Envies the peacefu lodding ploughman. QUE.

THE LAST JOURNEY. (From Blackwaod’s Magazine.)

Minuet), in his description of an Egyptian funeral processinn,_which he met on its way to the cemetery of Rosetta, says, “ The FYOCCSIIOH we IBW pass, stopped before certain houses, and sometimes receded a few steps. I was told that the dead stopped thus before the .door of their friends,to bid them a last farewell ; and before those of their enemies, to effect a reconciliation before they parted forever.”—Correspondence li’ Orient parM Michaud ct Poujoulat.

Slowly, with measured tread, Uplift your load again ! _ Onward we bear the dead Take up the mourning strain ! To his long home. Pour the dee wail!

Short rows the homeward road, Lo! the cxpecte one On wi your mortal load, To his place passeth on ; 0 grave ! we come. Grave! id him hail.

"Yet, yet,—ah! hasten not Past each remembor’d spot Where he hath been ; Far from our night ; ‘Where late he walk’d in glee, Let the air breathe on him, There from henceforth to be lAnd the sunbeam on him Never more seen. Last looks oflight.

Yet, yet,--ah! slowly move ; Bear not the form we love

Here dwells his mortal foo: Lay the departed low, Even at his gate. Will the dead speak again, Uttering proud boasts and vain, Last words of hate 1

Yet, yet,—ah ! slowl y move,—

Bear not the form we love Fast from our sight;

Let the air breathe on him,

And the sun beam on him Last looks of light.

Restyc,-Iet down the bier, One he loved dwelleth here. Let the dead he A moment that door beside, \Vont to fly open wide Ere he drew nigh.

1.0! the cold lips unclose;

List! list ! what sounds are those, Plaintive and low 7

“ O thou, mine enemy,

Come forth and look on me,

Ere hence I go.

.Hearken l—he spenketh yet ; ” Curse not thy focman now ; 'Mark on his pallid brow Whose seal is set !. Pardoning I pass’d away ; Then wage not war with clay,— Pardon,——forget."

(Friend more than brother!) How hand in hand we’ve gone, Heart with heart link’d in one,

All to each other 7

' 0 friend! lgo from thee, Where the worm feasteth free, Darkly to dwell. Givest thou no parting kiss? Friend l is it come to this? 0 friend! farewell.”

Now his last labour’s done! Now, now the goal is won! gravel we come. Seal up this precious dust; Land ofthe good andjust, Take the soul borne !

CALORIC, ITS NATURE AND PROPERTIES. A LECTURE, Delivered before the Charlottetown Mcchanics' Institute, on. the 21st December, 1842. Br 'riin REV. JAMES VVADDELL, First Vice Patron 9/ the Institute, and Master in the Central Academy.

(Concluded)

But does any one reply, we can neither mount to the upper regions of the air, nor betako ourselve to the polar seal, to test the truth ofyour theories: let us have some il- lustrations which fall within the reach of our own obser- vation. The demand is reasonable, and shall be complied wrtb,and then shall we take leave ot'this part ofthe subject.

. Place one end ofu rod of'iron in the fire, and in a short time, the heat will have so pervaded the whole length of it, that you cannot touch the other end without danger of being burnt; while you may with safety hold a much shorter piece of wood in your hand, when the end of it is blazing—so much more readily in caloric transmitted through the iron than the wood. Upon this principle it is, that urns, cofl‘ee pots, tea pots, and other metallic vessels, used for con- tainingliot flutds, are often furnished with ivory, bone or wooden handles, which, being imperfect conductors, inter- rupt the passage of the heat to the hand. When the hand grasps a bodycolder than itself, it becomes sensible of cold, because it portion of it heat is conducted away by the colder body; but if it come in contact with a body hotter than itself, it receives a portion of heat, and experience the sen- sation of warmth—and the intensity of the sensation, in either case, Will be in exact proportion to the conducting power of the body grasped. The carpet, in a room of mode- rate temperature, feels nearly us warm as the band; the to- bles and other wooden furniture are much colder to the touch; the stone or marble chimney piece is still colder; and tho fire-irons coldest of all. All these, however, it is evident, must be of prectsely the some temperature—the difference of? the sensation arises entirely from the greater or less rapi- dity With which they severally conduct away the heat from g the body. Thus does it appear that our sensations of heat and cold are merely relative. Snow is cold to a healthy finger; but it is applied to a frost-bitten limb, to cominuni~ one heat in the most gradual manner.

I have already stated, that sensible heat may be excited by mechanical agency. If two hard substances be robbed firm- ly together, heatis evolved. Thus, ifnn ungreased wheel be rapidly turned for a long time upon its axle, so much caloric ll excited as to cane them to burst out into a flame. The effects of powerful friction are known to savage nations, who often. kindlefires by rubbing two sticks together. The collision of flint and steel is a very familiar example ofthe mechanical means employed to produce fire, which ‘is heat m its extreme form ; 'and it is well known that iron hammer- ed for any length of time may, by that menus, be made quite hot. fleet is evolved also by chemical combinations, and the mixture of cold substances may be made to produce even rapid combustion.

Though he substance in nature can be said to be destitute of caloric, it is found to exist in different bodies in very dif- ferent degrees. “The proportion which one body bears to another, inrelatmn to its capacity for heat, is called its com- parative or specific caloric. By the capacity of heat, is to be understood, the disposition or property by which bodies require more or loss ofit to produce equal changes in their temperature. _For example, a pound of mercury, at the same temperature, ll found to contain no more than one-thirtieth part of the caloric contained in a pound of water. The comparative heat of mercury, therefore, is to water as 1 to 30.

It is found that the capacity of the same body is least when solid, greater when fluid, and greatest of all when converted into vapour-nor elastic fluid. Thus, when ice is converted into water, it absorbs us much heat as would ifit did not melt it, raise its temperature 140 degrees. in the other zinpd, before water can be converted into ice, it must after being reduced to 32 degrees, part with this 140 degr’ees of

1

heat, which occasioned it to exist in a ’fluid form. It is on this account that the processes 'offpeezmg and thawmg are such slow operations. Were it not for this, the frost'of a single night might freeze an ocean, and the heat ofa Single day convert the accumulated snows of winter'into a. sudden and frightful inundation. The convermon of_the same sub. stance into vapour so for increases its capacuy for caloric, that it absorbs a quantity which, but for this change ofstate, would raise its temperature nearly 1000 dcgreea;_or per- haps the subject will be better understood, when it 15.0b- server}, that in the condensation of steam into water, it gives out an amount of caloric which would raise an equal quan- tity of non—evaporable matter, ofthe same capacity wnli wa- ter, nearly 1000 degrees—and hence the severity ofthe scald occasioned by condensed steam from exploded engines may be readily accounted for. -

Perhaps it will have been remarked, that prevrous to re; fol-ring to different degrees of heat, 1 should have explained what is meant by the expression, and given some account of the instrument by which these degreesare ascertained. This I should have done, but that, to save time and repetition, I wished to reserve that explanation to illustrate one ofthe mechanical effects ofcaloric; and to these I shall now direct your attention. . I . -.’

The first in order is expansion or repulsron, which 15 cf-

bodies, and causing them to dilate in every direction. Of this a familiar illustration is aflbrdcd in the'rising of'the mercury in the Thermometer—an instrument in which this principle in applied to ascertain the_ temperature of the at- mosphere, or the amount of heat which it contains. lt-cone sins ofa glass tube, with a bulb at the bottom, into which a quantity of mercury or quicksilver is inserted, and after the atmosphere has been excluded, by boiling the mercury, the tube is hermetically sealed at the top, and fixod to a gradu- ated scale, which marks the rising or falling of the liquid in proportion as it is heated or cooled. \Vhen exposed to a higher temperature, the mercury, being laterally confined, is forced upwards by the expanding powor of the heat, and when that heat is withdrawn, it sinks in a corresponding de- gree. The Thermometer in common use in this country and in Britain is Fahrenheit’s, which is graduated or num- bered, in both directions, fi'om a point marked with n cipher, 32 degrees below that at which water freezes. 32 is marked freezing; 55 moderate heat; 76 summer heat in Grout Bri- Iain; 98 the heat oftho blood in the average of living men; and 212 the point at which water boils. Other Thermome- tors, similar in construction, but differently graduated, are employed on the continent ot‘Europe ; but it is desirable that, for readiness and accuracy of calculation, the same standard should be universally employed. Thermometers ofthis kind are used only to measure the intermediate degrees of heat, between 600 above, and 40 below zero, on at these points, respectively, mercury freezes and boils. Higher degrees of temperature are necessary, in the cultivation of the arts, and they are measured by an instrument which may be here~ utter described. Many familiar instances might be mentioned ofthe expansion of bodies by the application of caloric. A bar of iron is both longer and thicker when heated than when cold. The knowledge ofthis fact lends smiths who iron cart or other wheels, to heat the rim before they put it on, that it may be so enlarged as to slip easily into its place, and yet sufliciently small to bind the wheel fast when it is cooled. The boiling of water is another illustration of this property of heat. When water is placed in a full vessel on the fire, its particles become gradually heated. Those nearest the fire are heated first, and from their increased lightness, are repelled to the surface, while the colder and heavier par- ticles on the top sink to the bottom, and are heated in turn; and this process goes on till the whole quantity is raised to 212 degrees, the boiling point, when it rises in bubbles and ovorflowa the vessel in which it was held. Beyond this it is not possible to heat water, unless it is confined, as it then becomes converted into vapour. It is a waste of fuel to at- tempt to boil any substance quickly, which only needs to be exposed to a boiling temperature, as the extra heat goes to produce vapour, without increasing the temperature.

The process ofti'eeziug Water is, to a certain extent, the converse of this. Ifn quantity of water, at a temperature above 40 degrees, be exposed to a colder stratum ofuir, it gives out a portion ofits caloric, and is reduced to a smaller compass, till it is all cooled down to 40 degrees. At this point, the general law of nature is reversed, and instead of continuing to be condensed by the radiation of its heat, it begins to expand as the process ofcooling goes on, and con- tinue. so to do till ice is formed on the surface, which, as has been already stated, takes place at 32 degrees. Besides this peculiarity in the freezing ol'watei', which strikingly illustrates the goodness and wisdom ofGod, inasmuch as, were the ordinary process to continue throughout, the rivers and lakes, in climates such as ours, would, duringa very short period, be converted into solid masses ofice, which the heat 0er whole summer would scarcely dissolve, and all the sentient inhabitants oftlie' waters would be destroyed ; be- sides this, I say, there are n variety'of'instances in which this law is reversed, and bodies are found to contract, instead of expand, by the absorption of heat. Ice, it is Well known, in proportion as it is exposed to intense cold, expands, and, if confined, bursts the strongest vessels, while the application

of heat reduces it back to a smaller compass. Iron, reduced

to a very low temperature, likewise expands, and is thus ren- dered brittle in extremely cold weather. Ai‘gillaceous or clayey substances uniformly contract with the application of caloric, and of mnterials ofthis description has a very useful thermometer been constructed to ascertain very high degrees of heat. It was first presented to the Royal Society by Mr. Wedgwood, and bears his name. Having ascertained that clay, after being raised to a red heat, was coutracted in pro- portion to the quantity of caloric which it contained, he made a frame, consisting ot'two bars, fixed on a plane, a little fur- ther asunder at one end than at the other, leaving an open space between them. He then formed small pieces of clayey matter, fitted to enter at the wide end. These be exposed to intense heat, and by applying them to the scale or guage which he had constructed, he was enabled to ascertain with accuracy the extent to which they had been heated, by ob- serving how far they they could be made to slide towards the narrow end. The range of this thermometer is from red bent, visible by day, which corresponds to 1,077 degrees of Fahrenheit’s scale, ifit could be carried so high, to a point which answers to 32,277 of the same scale. By this instru- ment, the heat of furnaces used to fuse or melt metals is as- certained, and it is in this way essentially serviceable, as, without some guide of this description, the most precious materials might be destroyed by being allowed to be over- heated.

The next effect of caloric, after expansion, that come to honoured, is liquefaction, or the conversion of solids into fluxds. With this process all are familiar—and as I have already occupied your attention so long, 1 shall here, and in the remaining observations, be an briefas the subject will permit. Ofliquefaction, the melting of'ice is a ready illus- Atration, as is the fusion of the various metals. 1n proportion to the density of the body is the quantity ofcaloric necessary to reduce it to a liquid state. Ice melts at a temperature of 32 degrees Fahrenheit; Tin at 408; Lead, 540; Brass, 3,807; Fine silver, 4,717; Fine gold, 5,237; Cast iron, 21,877.

Evaporation is also produced by heat. Water affords a good example of this, as it is easily vaporioed, or converted into vapour; indeed, it undergoes spontaneous evaporation at very low temperatures. An immense quantity of water is continually rising from the surface of the earth, in the form of vapour, which, being condensed by giving out itsheat, is collected into clouds, and descends in the form ofrain or snow. Evaporation is always accompanied by the abstrac- tion of heat. _Ifa quantity ofvolatile fluid be applied to the temples, or, indeed, to any exposed part of the body, an it dries'oway, or is converted into vapour, the sensation of cold- nose improduced. By a knowledge of this fhci, persons r8- siding in hot countries, where ice is a great luxury, are en- abled to produce it by artificial means.

Vaporisotion is the process of evaporation, carried to a greater extent, or is the generation ofsteam by artificial means. By this process is the powerful agent obtained now so extonsrvely employed in steam navigation. In the form of vapour, water occupies 1,728 times greater space than

when in its fluid form; and it is this tendency to expand—

ciiccqtaummcmw.

fected by the iiisinuntion of caloric between the particles of,

and it can, by the continued application of anions, go to expand to an indefinite extent—what ren er:1 r sum g6 .- when properly leicrliployed, and so dangeious w on .

‘ ’ controuc . _ . cmfiihiiillation also is one of the practical purposesto a. knowledge ofthis princtple. is applied. It consists I m- production of vapour by caloric. A liqiud containing nip : portion of'saccharine mutter is exposed to it proper diezh, and the spirituous particles of the substpnce are currie _o d, and condensed by pqssiilig through a tune, made to Win

a uantit o co wa er.- \ I

th'Xllasthllidg and fluids which are not converted into vapour ate. less elevated temperature, become luminous whenlpeut‘; ed to 800 degrees in the dark, and 1000 in dnylig‘l‘it. it": light appears at first, and gradually passes to a iii] no, as to temperature increases. This is . observed equa y in corn- bustible solids, as charcoal, and in stony and other matters; which do not burn. They arfe then said to be in a'stgte o incandescence, or ignition. This is the form in whic “‘1; most familiar to us alll, aqfil Without which our long, co

‘ rs would be into era 9. . . Wl'YII‘tdetho chemical effects ofcaloric, l have, m some.in- stances, already incidentally advertcd {and I caught prescqt, only farther observe, that in all chemical combinations 1 s

equilibrium is disturbed, and the capacity of'tbo new sub-

stance formed is different from that ofthe indiVidual mute- riirls of'which it is composed. In some. processes, latent co- lor-ic'is evolved, and made apparent, as_in the case of slaking lime, which you have probably all wunessed. Sometimes so great a quantity of caloric is set free. nsito produce corn- bustion and deterioration. Ofthis a familiar gnstanceis afford— ed in the common matches prepared. with a mixture of chlorate of potass and loaf sugar, which ignite when brought into contact with sulphuric acid. .

It is supposed to be by this means that natural heat is en- gendered in living animals. The circulation of the blood is an active chemical process. and while it is‘regularly carried on, a genial warmth is excited; but when it is impeded or ac- celerated, the system becomes proportionally depressed by cold or stimulated by heat. v , '

In other combinations, caloric is absorbed,and enters into the latent state, when the sensation of cold is produced to a very great degree. This is seen in the variety of freezmg mixtures, of which that composed of‘mur'iute ofmodn (com- mon salt) with snow, at 32 deg, which immediately sinks the thermometer to zero, nfi'ordsa familiar illustration. Lpon this principle it is, that cooling beverages are obtained in hot clima‘tes at all seasons, and in the beat of our summers, by means of highly evaporable liquids, or the variety of of- fervescing mixtures. . .

Thus have I brought under your rewew a variety of facts and circumstances connected with this interesting subject. 1 make no apology for the crude and imperfect_maiiner in which 1 have presented them for your conmderation. They have been hurriedly collected from. the stores of my own mind, and such limited sources of information as I could make available. They have been thrown together at inter- vals of pressing avocatipns, and are now submitted,for the purpose ofpromoting, if'they can, the interests of this Insti- tute. l have endeavoured, as for as posmble, to avord the technicalities of Science, that I might be intelligible to all. I have rejected nbstruse calculations, that 1 might not per; plex—nnd in the choice of illustrations, when circumstances would permit, 1 have selected them from the great store- house of nature, that, by this means, I might lead you toa contemplation of the perfectionn of Nature’s God; that while woendeuvour to become wiser, we may learn to be better, and to cherish an habitual sense of our constant obli- gation to that great and glorious BEING, concerning whose works it is so justly remarked, “In wisdom hast thou made them all 1”