Part 78

When in a tranquil state, the colour of these brilliant inhabitants of the ocean is an opal yellow, mixed with green; but, on the slightest movement of those voluntary contractions exercised by the creature, or those which the observer can at pleasure excite by the least irritation, the animal seems to inflame, and it becomes instantly like a piece of red-hot iron of the most vivid brilliancy. When its phosphorescency declines, it assumes a succession of light elegant tints, that are very pleasing to the eye, such as red, aurora, orange, green, and azure blue; the last is particularly lively and pure. The organization of this animal, which is called the Pyrosoma Atlanticum, ranks it amongst the most singular of the zoophite tribe; whilst its extraordinary phosphoric powers render it the most beautiful that has yet been seen.

It may be not amiss to conclude this chapter with an account of that very curious substance, PHOSPHORUS.--This singular production was accidentally discovered, in 1677, by an alchymist of Hamburgh, named Brandt, when he was engaged in searching for the philosopher's stone. Kunkel, another chemist, who had seen the new product, associated himself with one of his friends, named Krafft, to purchase the secret of its preparation; but the latter deceiving his friend, made the purchase for himself, and refused to communicate it. Kunkel, who at this time knew nothing further of its preparation, than that it was obtained by certain processes from urine, undertook the task, and succeeded. It is on this account that the substance long went under the name of Kunkel's phosphorus. Mr. Boyle is also considered as one of the discoverers of phosphorus. He communicated the secret of the process for preparing it, to the Royal Society of London, in 1680. It is asserted, indeed, by Krafft, that he discovered the secret to Mr. Boyle, having, in the year 1678, carried a small piece of it to London, to shew it to the royal family; but there is little probability that a man of such integrity as Mr. Boyle would claim the discovery of the process as his own, and communicate it to the Royal Society, if this had not been the case. Mr. Boyle communicated the process to Godfrey Hankwitz, an apothecary of London, who for many years supplied Europe with phosphorus, and hence it went under the name of English Phosphorus. In the year 1774, the Swedish chemists, Gahn and Scheele, made the important discovery, that phosphorus is contained in the bones of animals; and they improved the processes for procuring it.

When phosphorus is heated to the temperature of 148°, it takes fire, burns with a bright flame, and gives out a great quantity of white smoke. Phosphorus enters into combination with oxygen, azote, hydrogen, and carbon. Phosphorus is soluble in oils, and, when thus dissolved, forms what has been called liquid phosphorus, which may be rubbed on the face and hands without injury. It dissolves too in ether; and a very beautiful experiment consists in pouring this phosphoric ether in small portions, and in a dark place, on the surface of hot water. The phosphoric matches consist of phosphorus extremely dry, minutely divided, and perhaps a little oxygenized. The simplest mode of making them, is to put a little phosphorus, dried by blotting paper, into a small phial; heat the phial, and when the phosphorus is melted, turn it round, so that the phosphorus may adhere to the sides. Cork the phial closely, and it is prepared. On putting a common sulphur match into the bottle, and stirring it about, the phosphorus will adhere to the match, and will take fire when brought out into the air.

CHAP. LXVIII.

CURIOSITIES RESPECTING VARIOUS PHENOMENA, OR APPEARANCES IN NATURE.--(_Continued._)

_Spots in the Sun--Diminution of the Sun--Parhelia, or Mock Suns--Eclipses--Halo, or Corona; and similar Appearances--Falling or Shooting Star--Volcanoes in the Moon._

Hail, sacred source of inexhausted light! Prodigious instance of creating might! His distance man's imagination foils; Numbers will scarce avail to count the miles. His globose body how immensely great! How fierce his burnings! how intense his heat! As swift as thought, he darts his radiance round To distant worlds, his system's utmost bound; Of all the planets the directing soul, That heightens and invigorates the whole. _Brown._

SPOTS IN THE SUN.--The following account of the spots in the sun is taken from a French paper.

"The spots were seen for the first time in 1611; and nearly about the same time by J. Fabricius, at Wittenberg, by the Jesuit Scheiner, and by Galileo. This great man watched their course with so much attention, and so well developed their phenomena, that very little has been since added to the descriptions which he gave, except more precise measures. The spots of the sun are at present viewed with astronomical telescopes, in which the great brilliancy of that luminary is mitigated, and not effaced, by the coloured glass placed between the telescope and the eye. There are in the interior of the telescope, at the focus of the object, some very fine threads stretched crosswise, and moveable parallel to each other, by means of which the distance of the spot from the nearest border of the sun's disk may be ascertained, which determines its position on the disk at the moment of observation. By following in this manner the same spot for several days, it is perceived to change its place. Its size also varies much. The spots sometimes grow thinner, and disperse from one day to another: and hence it is, that, though in one month rather a large number was visible, in the following only two are to be seen. But during the whole time of their presence they pursue a regular course, of which the aspects are common to all.

"When they first come in sight, they appear on the sun's border, like a slender thread. In proportion as they advance towards the middle of the disk, they appear, from day to day, to enlarge in the direction of their movement. They then decrease periodically; and if they last long enough to traverse the whole disk, they go off by the opposite side, narrowing to a single thread. These appearances are evidently such as a small body, adhering to a spherical surface, and revolving with or upon that surface, must present. The diminution of the spots, in proportion as they approximate the borders of the disk, results from this--that they then project more obliquely, and are only seen sidewise; but when in the middle of the disk, they are seen in their full extent. In fine, upon comparing the direction and rapidity of their course, it soon becomes evident, that the supposition of their adhering to the body of the sun is the only admissible one. On thus tracing the route of all those which appear, it is ascertained that they move in courses exactly parallel, describing circles which all have their centre on a common axis, passing through the centre of the sun. The size of these circles varies on different points of the disk, according to the same laws as on a sphere; and the rate of movement is modified in such a way, that all the circles are run through in equal times. This perfect concordance of revolution in spots so changeable in other respects, evidently shews that they must be attached to one and the same round body, which makes them revolve altogether with a common motion. Hence it has been concluded, that the sun revolves upon itself with the general motion of these spots, that is, in twenty-five days and a half, in like manner as our earth revolves in twenty-four hours. The same calculation, applied to the spots which have been discovered on the other planets, has in like manner made us acquainted with their rotation.

"As to the nature of these solar spots, it is absolutely unknown. Herschel is of opinion, that luminous clouds float in the inflamed atmosphere of this luminary, as clouds of vapour float in ours. He supposes that the body of the sun is opaque and dark; and that the black spots observed there at intervals, are merely the summits of very elevated mountains, which the solar clouds permit us to see between their openings. Other astronomers think that the globe of the sun is on fire, and that the spots are merely immense scoria, launched on the surface of that mass by some terrible explosions, of which our terrestrial volcanoes afford but a feeble picture. But whatever may be thought of these conjectures, it seems sufficient for us to know, that the solar spots are trifling compared with the immense mass of that body; and that the eruptions, of which they are perhaps the effect, take place at too great a distance from our earth to produce the least effect upon it. Generally speaking, the physical state of our little world is incomparably more stable and steady than its moral state."

DIMINUTION OF THE SUN.--Baron Lindeneau, who recently published a work on the diminution of the solar mass, says, that the sun may have been imperceptibly subject to successive diminution since the science of astronomy has been cultivated. Baron Lindeneau supposes the sun's diameter to be 800,000 miles, 4,204,000,000 feet, or nearly 2000 seconds. We have not, he observes, hitherto possessed any instrument for measuring the diameter of the heavenly bodies to a second. The sun may therefore diminish 12,000 of its diameter, or 2,102,000 feet, without the possibility of being perceived. Supposing the sun to diminish daily two feet, it would require _three thousand_ years to render the diminution of a second of its diameter visible.

Account of those singular Appearances, called, PARHELIA, OR MOCK SUNS.--

As when two suns appear in th' azure sky, Mounted in Phoebus' chariot fierie bright: Both darting forth fair beams to each man's eye; And both adorn'd with lamps of flaming light, All that behold such strange prodigious sight, Not knowing nature's work, nor what to weene, Are wrapt with wonder, and with rare affrighte. _Spenser._

A Parhelion is a meteor in form of a bright light, appearing on one side of the sun. Phenomena of this kind have been mentioned both by the ancients and moderns. Aristotle observes, that in general they are seen only when the sun is near the horizon, though he takes notice of two that were seen in Bosphorus from morning till evening; and Pliny has related the times when such phenomena were observed at Rome. Gassendi says, that in 1635-1636 he often saw one mock sun. Two were observed by M. de la Hire in 1689; and the same number by Cassini in 1693; by Mr. Grey in 1700, and by Dr. Halley in 1702; but the most celebrated phenomena of this kind were seen at Rome by Scheiner; by Muschenbroek at Utrecht; and by Hevelius at Ledan. By the two former, four mock suns were observed; and by the latter, seven. Parhelia are apparently of the same size with the sun, though not always of the same brightness, nor even of the same shape; and when a number appear at once, there is some difference in both respects among them. Externally they are tinged with colours like the rainbow; and many have a long fiery tail opposite the sun, but paler towards the extremity. Parhelia are generally accompanied with coronas, some of which are tinged with rainbow colours, but others are white. (See _Halo_.) They differ in number and size; but all agree in breadth, which is that of the apparent diameter of the sun. A very large white circle, parallel to the horizon, generally passes through all the parhelia; and, if it were entire, it would go through the centre of the sun. Sometimes there are arcs of lesser circles concentric to this, touching those coloured circles which surround the sun. They are also tinged with colours, and contain other parhelia. Other circles are said to have been obliquely situated with respect to all these. The order of the colours in these circles is the same as in the rainbow; but on the inside, with respect to the sun, they are red, as is also observed in many haloes. Parhelia have been visible for one, two, three, and four hours together; and in North America, they are said to continue some days, and to be visible from sunrise to sunset. When the parhelia disappear, it sometimes rains, or snow falls in the form of oblong spiculæ, as Maraldi, Weidler, Krafft, and others, have observed; and because the air in North America abounds with such frozen spiculæ, which are even visible to the eye, according to Ellis and Middleton, such particles have been thought to be the cause of all coronas and parhelia.

Mr. Wales says, that at Churchill, in Hudson's Bay, the rising of the sun is always preceded by two long streams of red light, one on each side, and about twenty degrees distant from him. These rise as the sun rises; and as they grow longer, they begin to bend towards each other, till they meet directly over the sun, just as he rises, forming there a parhelion, or mock sun. These two streams of light, he says, seem to have their source in two other parhelia, which rise with the true sun; and in winter, when the sun never rises above the haze or fog, which he says is constantly seen near the horizon, all these accompany him the whole day, and set with him. Once or twice he saw a fourth parhelion, directly under the sun; but this is not common. These facts being constant, are very valuable, and may throw great light on the theory of these remarkable phenomena. Sometimes parhelia appear in a different manner; as when three suns have been seen in the same vertical circle, well defined, and touching one another. The true sun was in the middle, and the lowest touched the horizon, and they set one after the other. This appearance was seen by Maleziew, in 1722. Other appearances similar to this are recited by Mr. Muschenbroek. Sometimes the sun has risen or set with a luminous tail projecting from him, of the same breadth with his diameter, and perpendicular to the horizon. Such an appearance was seen by Cassini in 1672 and 1692; by De la Hire in 1702; and by Mr. Ellis in Hudson's Bay. As M. Feuilée was walking on the banks of the river La Plata, he saw the sun rising over the river, with a luminous tail projecting downwards, which continued till he was six degrees high. Paraselæ, or mock moons, have also been seen, accompanied with tails and coloured circles, like those which accompany the parhelia. An account of several, and a particular description of a fine appearance of this kind, may be seen in Muschenbroek.

The following account of this phenomenon is extracted from a pamphlet, entitled, 'Somewhat written by occasion of Three Sunnes' seene, at Tregorie, in Cornwall, the 22nd of December last; with other memorable occurrents in other places. Imprinted 1622: 20 pages small 4to.'

"Since this strange apparition, namely, upon the 10th of January last, there happened in Devonshire, yet not farre from the other place, being on the edge of Cornwalle, another wonder, which, did as much affrighte the eares of men, as this did their eyes: for in the afternoone of that day, being the Thursday after Twelfth-day, there were heard in the aire unusuall cracks or claps of thunder, resembling in all points the sound of many drums together, sometimes beating charges, sometimes retreats, sometimes marches, and all other points of warre: which, after it had continued a good time, it seemed that the same thunder did most lively expresse many volleyes of small-shot, and afterwards the like volleyes of ordnance, with so great and yet so distinct noyse, that many of them who dwelt neare the sea, went toward the shore to see what it might meane, as verily supposing there had beene some sea fight neere upon that coast. These severall fearfull noyses were againe and againe renewed in the same order, till at length with an horrible and extraordinary cracke of thunder, there fell in a ground of one Robert Pierce, where there were divers workemen planting apple-trees, (which ground lay neere the house of one Master George Chidley,) a thunder-bolt, if I may so call it, being a stone of three foot and an halfe in length, of two foot and an halfe in breadth, and one foot and an halfe in thicknesse, the substance whereof was in hardnesse and colour not much unlike a flint, as appeares by many pieces thereof, which are shewed up and downe by many credible and honest gentlemen, who, with their own hands, brake them off from the maine stone. After the fall of this stone, which with the weight thereof was cleane buried in the ground above a yard deepe, the thunder ceased, and people began as much to won--at that which they now saw, as they had lately done at that, which with so much feare and amazement they had heard."

Observations on ECLIPSES OF THE SUN AND MOON.--

Give me the ways of wand'ring stars to know, The depths of heav'n above and earth below; Teach me the various labours of the Moon, And whence proceed th' Eclipses of the Sun. _Virg. Georg._ ii

The deprivation of the light of the sun, or some heavenly body, by the interposition of another heavenly body between our sight and it is, called an Eclipse. Thus, eclipses of the sun happen by the moon's intervening between it and the earth; by which means the shadow of the moon falls upon the earth, when the latitude of the moon does not prevent it, by elevating her orb above, or depressing it below the earth. On the other hand, an eclipse of the moon can only happen when the earth is interposed between the sun and it; for then, if the latitude of the moon does not prevent it, the shadow of the earth may fall on the moon, and thereby cause either a partial, or total eclipse. A total eclipse of the sun or moon, is when their whole bodies are obscured; and a partial one, is when part only of their bodies is darkened: again, a central eclipse is when it is not only total, but the eclipsed body passes through the centre of the shadow.

As total solar eclipses are by no means common, we shall give an interesting description of one, by Dr. Stukeley, sent to his friend, the celebrated Dr. Edmund Halley.

"According to my promise, I send you what I observed of the solar eclipse, though I fear it will not be of any great use to you. I was not prepared with any instruments for measuring time or the like, and proposed to myself only to watch all the appearances that nature would present to the naked eye upon so remarkable an occasion, and which generally are overlooked, or but grossly regarded. I chose for my station a place called Haradon Hill, two miles eastward from Amsbury, and full east from the opening of Stonehenge avenue, to which it is as the point of view. Before me lay the vast plain where that celebrated work stands, and I knew that the eclipse would appear directly over it; besides, I had the advantage of a very extensive prospect every way, this being the highest hill hereabouts, and nearest the middle of the shadow. Full west of me, and beyond Stonehenge, is a pretty copped hill, like the top of a cone, lifting itself above the horizon; this is Clay-hill, near Warminster, twenty miles distant, and near the central line of darkness, which must come from thence, so that I could have notice enough beforehand of its approach. Abraham Sturgis and Stephen Ewens, both of this place, and sensible men, were with me. Though it was very cloudy, yet now and then we had gleams of sunshine, rather more than I could perceive at any other place around us. These two persons, looking through smoked glasses, while I was taking some bearings of the country with a circumferentor, both confidently affirmed the eclipse was begun, when, by my watch, I found it just half an hour after five; and accordingly from thence the progress of it was visible, and very often to the naked eye; the thin clouds doing the office of glasses. From the time of the sun's body being half covered, there was a very conspicuous circular iris round the sun, with perfect colours. On all sides we beheld the shepherds hurrying their flocks into fold, the darkness coming on; for they expected nothing less than a total eclipse for an hour and a quarter.

"When the sun looked very sharp like a new moon, the sky was pretty clear in that spot; but soon after a thicker cloud covered it, at which time the iris vanished; the copped hill before-mentioned grew very dark, together with the horizon on both sides, that is, to the north and south, and looked blue, just as it appears at the declension of day. We had scarcely time to tell them, when Salisbury steeple, six miles off southward, became very black; the copped hill was quite lost, and a most gloomy night with full career came upon us: at this instant we lost sight of the sun, whose place among the clouds was hitherto sufficiently distinguishable, but now not the least trace of it was to be found, any more than if really absent: then I saw by my watch, though with difficulty, and only by help of some light from the northern quarter, that it was six hours thirty-five minutes: just before this, the whole compass of the heavens and earth looked of a lurid complexion, properly speaking, for it was black and blue, only on the earth upon the horizon the blue prevailed; there was likewise in the heavens, among the clouds, much green interspersed, so that the whole appearance was really very dreadful, and as symptoms of sickening nature.

"Now I perceived we were involved in total and palpable darkness, as I may aptly call it; for though it came quickly, yet I was so intent, that I could perceive its steps, and feel it as it were drop upon us, and fall on the right shoulder (we looking westward) like a great dark mantle, or coverlet of a bed, thrown over us, or like the drawing of a curtain on that side. The horses we held in our hands were very sensible of it, and crowded close to us, startling with great surprise; and as much as I could see of the men's faces that stood by me, they had a horrible aspect. At this instant I looked around me, not without exclamations of admiration, and could discern colours in the heavens, but the earth had lost its blue, and was wholly black. For some time, among the clouds, there were visible streaks of rays, tending to the place of the sun as their centre; but immediately after, the whole appearance of earth and sky was entirely black: of all things I ever saw in my life, or can by imagination fancy, it was a sight the most tremendous.