« 前へ次へ »
SCIENTIFIC MISCELLANY, NO. V.
ON LIGHT AND COLOURS. IN my last paper, I adverted to the other which constitute a ray of light,
nature and property of solar light, cannot with any accuracy be determinconfining my observations more parti- ed. If a burning stick be made to de cularly to the different coloured rays of scribe a circle by quickly turning it which it is composed. I now proceed round, the whole circumference will to consider some of its remaining pro- appear luminous; which shows that perties.
the impression made by the light upon The amazing velocity of light has the sensorium, when the stick is in any been treated of in a former paper; and one point of the circumference, remains therefore I need here merely remark, till the burning part of the stick returns that this fact was first demonstrated by again to the same point. Now it has Roemer, a Danish philosopher, who been found, that if the revolution of the proved that it requires about eight ignited body be performed in 7"", (or minutes to pass over one half of the seven sixtieths of a second, the whole earth's orbit, consequently, that light circle appears luminous: that is, if the moves at the rate of 200,000 miles in a particles succeed each other at an insecond. Notwithstanding, however, terval which does not exceed that time, this astonisbing velocity of its parti- constant vision is produced ; and since cles, their momentum is not so great as light passes over more than 22,000 to discompose the delicate texture of miles in 7''', if the distance of the parthe eye; and when a considerable ticles be not greater than 22,000 miles, quantity of its rays are collected in the they are sufficiently contiguous to anfocus of a powerful burning-glass, they swer the purposes of constant vision. are not capable of communicating the Newton supposes that the impression least motion to the thinnest laminæ of continues about a second of time. metal (gold leaf for example) which Light, when it comes in contact with can be exposed to their impact. bodies, is not only capable of entering
The wonderful divisibility of the into them; but likewise of remaining parts of matter is in nothing more ap- within them; and, in many cases, the parent than in the minuteness of the light thus absorbed may afterwards be particles of light. This divisibility of extricated without its having undermatter in general, may indeed be ma- gone any alteration. Mr. Capton thematically proved to be capable of made some ingenious experiments on being carried on ad infinitum ; but this subject.
He calcined* some oysthough we are constrained to admit the ter-shells in a good fire for half an possibility of the fact, yet we cannot hour, and then pounded and sifted the form any just idea respecting it. The purest part of them. Three parts of same difficulty of apprehension will at- this powder were mixed with one part tach to the minuteness of the particles of the flowers of sulphur, and rammed of light : but still it has satisfactorily into a crucible, which was kept red hot been shown, that a single inch of can- for an hour. The brightest parts of dle, while burning, is capable of giving the mixture were then scraped off, and out particles to the amazing number of kept in dry well-stopped phials for 269,617,040, with forty cyphers an- use. If they be exposed for a short nexed; at which rate there must issue, time to the rays of the sun, they will during one second of time, a number of thus acquire the property of emitting particles “ vastly more a thousand light in the dark, so as 10 enable a pertimes a thousand million times the num- son to distinguish the hour on his ber of sands which the whole earth it- watch. After some time, it ceases to self could contain, provided the whole
• To calcine is to burn in the fire to a were solid."
cals, or substance equally reducible to pow. How near those particles are to each der.
shine, but recovers its property on be ther, and on the seventh entirely disaping again exposed to the light. These pears. At this period, however, neifacts are curious, but we are not aware ther the flesh nor the liquid have any of any practical benefit which can re- smell of putrescence. Similar appearsult from their discovery. The sub- ances took place by the same treatstance formed as above, is termed py- ment of mackerel. rophorus and sometimes solar phos But the property of emitting light is phorus.t
not confined to either these solar pyloLight not only enters into bodies, it phori, or to the pyrophori made by soalso combines with them, and forms lutions of animal substances. There one of their component parts. It has are also living pyrophori ; such as the been long known, that different kinds glow-worm, lantern-fly, and many othof meat and fish, when they are begin- er insects. The luminous matter of ning to putrefy, become luminous in the glow-worm is a liquid secreted and the dark, and of course give out light; retained in the lower part of the abdothis is the case particularly with the men. If the fluid be squeezed out, it whiting, the herring, and the mackerel. still retains its shining property, and This phosphorescence of fish and ani- may be spread upon the palm of the mal substances was first investigated hand, but in this state it soon disap by Canton, who has furnished a num- pears. The light is most vivid when ber of interesting experiments. The the creature is in motion. Its luminous subject, however, has been more fully appearance, however, is at all times inentered into and extended by Dr. terrupted by periods of either diminishHulme.
ed light or total darkness. In its most If two drams of the flesh of herrings vivid state, the colour of the light emitbe put into a dram of sulphate of mag- ted is of a bright yellow or orange. nesia, (Epsom salts,) on the second Many sensible effects are produced evening a ring of light will be perceiv- on bodies by the absorption of light. ed round the top of the liquid, but it Plants, for instance, may be made to will still be dark below, but on shaking vegetate tolerably well in the dark the phial, the whole will become beau- but in that case colour is always white, tifully luminous. On the third night, they have scarcely any taste, and conthe light rises again to the top, but the tain but a very small portion of comring is not so luminous as on the pre- bustible matter. In a very short time, ceding night, nor the whole mixture however, after their exposure to the after shaking it. Sometimes the light light, their colour becomes green, their disappears entirely on the tbird even- taste is stronger, and the quantity of ing. A similar experiment may be combustible matier is considerably inmade with sea-water. In this case, creased. Celery, for example, reon the second night the liquid is dark, quires to be covered with earth, in oron the third lucid, on the fourth very der to its becoming an article suitable luminous, on the fifth it begins to de- for food; for by this means the light is cline, on the sixth diminishes still fur- excluded, which would very soon turn + Baldwin's Phosphorus, a similar com
it green, and would make its flavour so position, may be made as follows. Put strong as to render it upfit to be eaten. some dry nitrate of lime into a crucible, A strong attraction of affinity is obserand place it in a clear fire, and let it re vable between light and living vegetamain in a state of fusion for about ten min. bles. This fact is familiar to those who utes ; then pour it out into a warm iron vessel and it becomes solid ; break it into have placed trees in windows, for they pieces, and inclose them in well-stopped always lean towards the light. This phials. Expose these phials to the direct would be still more observable by rays of the sun for some hours, and when wholly confining them in a dark room, taken into a dark place they will give out into which light was admitted only by a considerable quantity of light. if muri. ate of lime be taken instead of nitrate, a small hole : they would first turn and and treated in exactly the same manner, then grow towards it, until they should a similar effect is produced. This lat- be able to get though it into the open ter substance is termed Homberg's Phos. phorus
(Lond. Lit. Gaz.)
His borse, who defer in that sort
drunk, Sir,' continued the Duke. Had handled been before,
Beg your pardon, (hiccup) your RoyWhat thing upon his back had got
al Highness-I am as sober (hiccup) Did wonder mere and more.”
as a prince.'- I say you're aboininaWAX as for the matter bly drunk, Sir.- Well, well, an't
oʻthat, (said old Jem please your Royal Highness, I may Breeching, knocking the ashes out of be (hiccup) about half seas over.' --his pipe, and preparing to recharge.) Then, Sir, my orders are, that you -As for the matter o’that, I've had all keep half seas over for the next week sorts of acquaintances, from Bet Blow. to come ; so go on board, get under sey, the bumboat woman, down to the weigh, and cruize at the back of the Duke of Wellington ; aye, and I've Goodwin till recalled.'
Aye, aye, been among Royals too. Why, there an't please your Royal Chiccup) Highwas the Duke of C him as took ness, I'll be off the Good-un directly ;' comidaod in the Downs at the first of and away he started. Poor Mich was the Peace, when all the Hemp-he-roars a jovial fellow, but Death grappled and Kings came to pay our honour'd him at last. He was a great favourite Majesty a visit under that 'ere thing- with all the Captains, and obtained his um-eye they 've got at Woolwich now commission partly through merit, and for a rot-under. There was a sight! partly on account of a humorous PoWe would'nt look at your common em address’d to the Lords of the Ado lords and ladies then. I remember miralty. I recollect once falling in old Blue-cheer landing, and Play-'toff with his vessel off the Texel. How Prince of Easy-Humbug, for I belong. are you, Mr: C-says our Comed to the yacht that took old Loo-be- mander, hailing bim. More troubled de-sweet to France; and so we saw with the wind than the weather, Sir, 'em all for nothing. But, somehow or (replied C ->) for my spirits are terother, there warn't one to beat our own ribly low. Can you spare me a few good old George ; and then there was nervous drops ?? Aye, aye ; let's that lovely flower of British growth, have something to put 'em in. Thank our own dear Princess Charlotte, so ye, Sir, thank ye; I'll send my Joey like her Royal Grandfather. There, (a three-gallon bottle to which he gave messmates, I won't say another word ihat name)—I'll send my Joey, The aboot it; I sees you're all affected. boat was lower'd down, and Joey came Some on you remembers the Countess aboard. The Captain, without noticof Elgin hired cutter, commanded by ing its size, ordered the Steward to fill Mich. C-ford, when Bobby H-it. • What are you about there below, was Master. Well
, d'ye see, Mich Steward ? (said the Commander ;) was ashore at Deal, with his jib bows. What makes you so long?' I han't ed chock a block, and turning the cor. half filled the bottle yet, Šir.' • Not half ner in Middle-street with fresh way, filled it!—why how much does it be come stem on, right into the Duke's hold ?' - Three or four gallons, Sir.' froll. “Halloo! halloo! (exclaimed "Confound the fellow ! Countess a-hoy!" His Royal Highness,) what ship do you « Halloo! _“I say, C-ford, belong to? No ship at all, (hiccup) you send your Joey aboard of me my Lord your Majesty, I inean, again, and I don't break his neck, Do you know this Officer enquired there's no snakes in Vir-ginny. Why the Duke, turning to Captain A-he's nearly swallowed all
my grog!'” * Know me, (said Mich, making ano “Ah, says old Ben Marlin,) them ther tack towards him,) aye, to be sure there were glorious times ! But, howhe does.' _Tis" the Commander of somever, we are never satisfied. When the cutter,” said Captain A-. You're we used to drink Malmsy Madeira
out 24 ATHENBUM VOL. 1. 2d series. of a bucket, the toast was always “Bet
ter luck still.' Touch the bell, Dick and tarts, rolled in all directions; it Wills.” “Aye, aye,' says Dick, rat- soon made a-bun-dance among the tling the poker and tongs together. small fry- barbers and sweeps, brick“ Landlord, said Ben, as he enter'd,) layers and tailors, my eyes! there was it's a sad heart as never rejoices; and precious work ! Well, old Harry disso, d'ye see, having received a present mounted, and taking his hanimal on of rhino from an old friend, why bring his shoulders, walks deliberately out, us in a bucket of flip for all hands." and sets him down in the street, orderThis was extremely welcome, and ve- ing 'em to send in their bill, and he'd ry gratefully acknowledged. The flip make good the damages. At last we was brought. “ And now (says Ben) clear’d the town, and formed the order I'll tell you a rum story, that happened of sailing in iwo divisioos. Black about twenty years ago this very day. Jackson, the captain of the main-top, Why aye, that was one of the rummest coinmanded one, and Jem Crampton rigs that ever I seed ; zounds, it put all the other, and the wind coming favourPortsmouth in a mutiny !"'_ Hoot, able, the signal was made to crack hoot ! (said old Hameish,) dinna mak on all sail. It was a fine sight to see twa bobs at a cherry, mon, but gie's the small craft scud out of our way, the account, and let's hae it wi’ muckle and the road was lined with spect-taglee; only bearing in memorial that toes to gaze at the fleet. Well, d'ye ?tis ane o' the rules of this Saucyation see, Tom Butt-you remember Tom that nae ane is to indulge i' the flights Butt, a comical crojack eyed fellow, as o' fancy, vulgo a lie, without its being dry as a biscuit when he was well barefaced, in contradistinction to the soak’d? Tom Butt had got a dull naked_truth. . Be aisey, Hameish, sailer, that wouldn't answer her helm, (says Teddy.) and don't make a both- and so he and Jack Moberly, whose eration. How can he lie while he craft was every bit as bad, were left sits? And as for lying at full length, astern. Tom, thinking she was out of och don't mention it-he'll never do trim and too much by the head, gets that again. Isn't he getting as straight out of the saddle, and shifts ballast faras a ram's horn ? Arrah, Ben, myther aft; that was worse, for his vessel darling, get on, and don't stop; do the luft right up in the wind, came athwart thing dacently—begin in the middle, Jack's bows, and capsized bim in an and make both ends meer.' “Why, instant; but that warn't the best of it: d'ye see, (says Ben,) it was that 'ere however, we had a glorious day, and time when most of the channel fleet next morning toss'd up our anchors for were at Spithead, and liberty-men Portsmouth. Well, poor Jack Moberwere ashore every day. Well, the old ly was taken before the Mayor by the Barfleur was going to be paid off, and rogue of a landlord that hired him the what does we do, but determined to horse, and all hands attended as withave a grand sheave-o before all hands nesses ; indeed it made such a kick up, separated. So we sends despatches to that hundreds were in attendance outFareham to have a good dinner ready side the court. Jack, his face plasfor us New Year's Day, with oceans tered and patch'd in all directions, was of grog and mountains of bacca; and put to the bar, the landlord on his so we muster'd that ere morning to the right, and Tom Butt on his left. 'Well, number of sixty or seventy, some on what is your complaint ?” said Sir horses, sone on donkeys; and as for C-ter. Why, please your worship, chaises and gigs, there was a pretty I hired this here fellow a horseset-out. Well, we weighed with a foul Fellow! (says Jack) who do you call wiod from Capstan-square, and after fellow ? I've got a collar to my shirt making a great many tacks, hove to as well as you. Don't interrupt him, before the Admiral's, and saluted him my friend,' said the mayor. There, with three hearty cheers. Harry Cole (replied Jack, slueing round to the was mounted on a Jerusalem poney, landlord,) doesn't his honour call me that backed astarn right through the friend ?---and shiver my old tarry window of a pastry-cook's shop. trowsers if I won't be a friend to your There was a dish of fummery, pies, worship as long as you live.' Well,
Well, let the man go on. "So I hired of tar; and then we brought him to a bim a horse. That's a cracker court-martial for losing his ship, but (says Tom Butt) as how it was no after a close flistigation of the case, he more like a horse than your honour, was honourably quided, for it was fulbut a broken-back'd rattle-trap ould ly-'. At this moment there was a mare ; and, belike your worship— terrible rookery and noise outside the "I must insist on one speaking at a court— See what's the matter there,' time, (said the mayor) and first let me said the mayor. The hubbub continuhear the man's complaint.' Why, ed, and the officer returned with a replease your worship, they hired any port that it was some sailors had mare, as capital a roader as ever was brought another witness. "Let 'em backed, thof I say it myself; she cost come in,' says the magistrate. The me- . But that has nothing to do doors were opened, and in came Joe with the concern! exclaimed the ma- Jarves, leading the ould mare. My gistrate. No, your worship: Well, eyes! there was a bobbery. The aniyesterday they brings her back again, mal was strips of plaster from stem to both knees broke, and her face cut to starn, and looked in a state of starvapieces, and so I threw her on his tion. I dare say the crows always hands, to make good the loss, but they followed her. Howsomever, Joe berefuse to satisfy me.' What do you gins— Look here, your worship, my estimate the worth of the beast?' messmate is in limbo for breaking this • Thirty pound, your worship, and lit- here creature's knees; now I say she -tle enough too. Well, my friend, ought to be clapp'd in limbo for breaking and what have you to say to that?' my nessmate's face, for that ere genus "Why, if you pleases (says Tom Butt) there said she had been over the road I'll overhaul the whole matter, for my hundreds of times; now Jack had nemessmate is rather taut bound about ver steered that course before ; which the upper works.' . Let me hear it ought to know best, your worship? then as quick as possible. Why But to prove the roguery of the thing, d'ye see, we met to have a bit of a jol- look, your worship, one bridle-port is lification, as all hands were going to be fast jamm'd and bolted in her bead, drafted into different ships. Well, and the other hasn't been opened since. your worship, the feet weigh'd from Then she had an ugly knack of stopthe town, and the commander in chief ping, and swinging one leg all manner made the signal to make all possible of ways, like a dog-vane in a calm. sail, and so they crack'd on, that I and We offered to make reparation, but he Jack here were left hull down astern. wouldn't agree to it, and swore he'd Well, your bonour, being willing to bring a civil action against Jack for drag up with the rear squadron, we the recovery of the beast. Whether carried a taut press, but a sudden squall this is a civil action to clap Jack in threw as slap aback, and Jack's vessel limbo I leave to your worship to judge; being crazy and leaky withal, turned and as for the recovery of the creature, the turtle with him, and, sure enough, didn't we try all we could to recover store in the animal's bows, and carried her? Didn't we fish her game-leg and away part of Jack's cut water, and sun- do the needsul,and hasn't she had strong dry other damages. Well, 'twas a beer to drink, while all the rest had blessed thing that the squall did hap- water ? and didn't we bring her pen, for the feet were obliged to shor- home in a coal-waggon, riding all ten sail; and so some an 'em was or- the way ? and if that warn't enough 10 dered to take him in tow. As soon as recover her, why she'll never be better.' the raia abated and the wind lullid, Old Joe's appeal, and the sight of the they carried on, and got to Farehain in mare, did the business ; we were orgond time. Jack Tempest made sail dered to pay five pounds and the docto the doctor's for six yards of plaster, tor's bill, and then all hands adjourned and so we parcell'd and woulded the to the Sally-port, where we drank suicshiver'd parts in both the beast and cess to the ould mayor of Portsmouth my messmate, giviog 'em a good lick and the ould mare of Common-hard.
AN OLD SAILOR.