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THE FUEL OF THE SUN.

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anchored near the beach, or transported

From The Gentleman's Magazine by steamboat or railway to their ultimate destination. A large quantity of

THE dazzling brilliancy of the sun the finest oysters are transferred to far exceeds all artificial sources of illubeds in other places, to be fattened, as mination. It has been shown experithis process cannot be brought to per- mentally that, compared with a standard fection in the locality.

candle placed at a distance of one metre A strict watch is kept by day and from the eye, the sun's light is cqual in night over the parks, so that no ama

quantity to fifteen hundred and seventyteur may try his hand at oyster-gather- live billions of billions of such candles ! ing. For this purpose are the numbers (Fifteen hundred and seventy-five folof houseboats which are to be seen dot-lowed by twenty-four ciphers). The ting the bay, their white roofs shining intensity of the solar light - or the in the sun. These contain bed and

amount of light per square inch of surboard for the guardians of the parks. face is found to be ninety thousand On the Ile des Oiseaux, in the ceutre times greater than that of a candle, and of the Bassin, are cabins for the same

one hundred and fifty times as bright purpose.

as the lime light! The blackest porThough hardly the place for a suc- tion of a sun-spot exceeds the lime cessful pearl-fishery, pearls have been light in intensity; and even the electric

, found in Arcachon on rare occasions.

arc, when placed between the eye and The local museum contaius as a curios

the sun's disc, appears as a black ity three found together in one shell some years ago. The only other occa

The question has often been asked, sion we know of was quite lately, when What is the fuel of the sun ? What is the writer himself was the lucky finder. the origin of the vast amount of heat

Great as is the number of oysters and light which is constantly being radiexported from Arcachon annually, it is aled by our central luminary into surestimated at not more than two per rounding space ? The question is a cent. of those born; and this is com- difficult one to answer, if looked at in paratively a very large proportion, due the light of actual combustion. The to the elaborate manner in which the

amount of fuel necessary to produce industry is carried on.

It has been the observed results is so estimated that for every oyster brought that it seems almost impossible to imashore from the natural beds of Ger- agine where the fuel could come from. many, more than one million die. The

Sir William Thomson bas calculated number to which a mother-oyster gives that the quantity of fuel required for birth is so large as to be almost incred- each square yaril of the solar surface ible, and of these only a very small would be no less than thirteen thousand proportion find their way to the chalk

five hundred pounds of coal per liour ! covered tiles placed for their reception.

- equivalent to the work of a steam Many of course are destroyed in the

engine of sixty-three thousand horsenumerous processes through which they power! This enormous expenditure pass during the three or four years nec- of fuel would be sufficient to melt a essary for such perfection as is attain- thickness of about forty feet of ice per able in the locality.

minute at the sun's surface. Sir John Altogether, it is an interesting indus- Herschel says, “Supposing a cylinder try, and one in which the picturesque of ice forty-five miles in diameter to be abounds. A pretty siglıt, the return of continually darted into the sun with the the boats on a full tide, after a day's velocity of light, and that the water prowork, when the many sails, white and duced by its fusion were continually terra-cotta, dot the clear blue water carried off, the heat now given off conunder a clear blue sky, with a grey line

stantly by radiation would theu be on the horizon, the distant, pine-covered saudbills,

1 Young's General Astronomy, pp. 212-214.

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wholly expended in its liquefaction, on about two hundred and fifty thousand the one hand, so as to leave no radiant miles of the sun's surface, and in this surplus ; while, on the other, the actual focus the most refractory substances temperature at its surface would un- platinum, fire-clay, the diamond itself dergo no diminution.” He also says - are either instantly melted or dissithat the ordinary expenditure of heat pated in vapor. There can be no doubt by the sun per minute would suffice to that if the sun were to come as near to melt a cylinder of ice one hundred and us as the moon, the solid earth would eighty-four feet in diameter, and in melt like wax.” Messrs. Trowbridge length extending from that luminary to and Hutchins consider that in the solar a Centauri !

atmosphere, where carbon is volatilized, As to the actual temperature at the the temperature is about equal to that sun's surface, very various estimates of the voltaic arc. have been made by different computers. It may be shown that were the sun's Secchi supposed it be about ten mil- mass composed of coal it would all be lion degrees of the Centigrade ther- consumed in about six thousand years. mometer! and Spörer thirty - seven It has been suggested that the solar thousand degrees of the same scale ; heat may possibly be maintained by the while M. Pouillet thinks that it lies fall of meteors on its surface. A pound between 1,461 and 1,761 degrees Centi- of coal falling on the sun's surface from grade. M. Becquerel, Professor Lang- an infinite distance would develop by ley, and Sir William Thomson consider concussion six thousand times the heat that the temperature of the solar photo- that would be produced by its combussphere cannot exceed three thousand tion. But the enormous quantity of degrees Centigrade. According to M. meteors required for the purpose Saint-Claire Deville, the temperature is about thirty-eight hundred pounds per somewhere about twenty-five hundred square foot per annum — renders this to twenty-eight hundred degrees, and theory very improbable. If the earth this agrees with subsequent experi- were to fall into the sun it would mainments by Bunsen and Debray. Sir tain its heat for a period of less than Robert Ball says that “ we shall prob- one hundred years. Jupiter falling ably be well within the truth if we into the sun would supply its present state the effective temperature of the expenditure for thirty-two thousand sun to be about eighteen thousand de- years to come ; but, in view of the grees Fahrenheit” (The Story of the millions of years indicated by geological Heavens, p. 495). Secchi's estimate is records, even this period must be probably very excessive, and the smaller considered comparatively short. determinations nearer the truth. The Another objection to this theory is actual heat of the sun must, however, that the quantity of matter required be very great. Professor Young says : would, in the course of ages,

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appreWhen heat is concentrated by a burn- ciably to the sun's nass, which would ing-glass, the temperature at the focus derange the motions of the planetary cannot rise above that of the source of system. The meteoric theory of the heat, the effect of the lens being sim- sun's heat must, therefore, be abanply to move the object at the focus vir- doned. tually towards the sun ; so that, if we The theory now generally accepted neglect the loss of heat by transmission by astronomers is that advanced by the through the glass, the temperature at eminent German physicist Helmholtz, the focus should be the same as that of which ascribes the heat of the sun to a point placed at such a distance from the shrinkage of its mass caused by the sun that the solar disc would seem gravitation. It may be shown mathjust as large as the lens itself, viewed ematically that this shrinkage would from its own focus. The most powerful undoubtedly produce the observed rclens yet constructed thus virtually trans- sult, and, as gravitation must inevitably ports an object at its focus to within 'act on the component particles of the

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sun's mass, it seems quite uunecessary | admit much more thau twelve million to look further for a satisfactory the years as the past duration of the suu'sory. The amount of shrinkage re- history, but, as I have showu ju a quired to account for the present solar former paper, this period — immense radiation is so small that the diminu- as it is — will not satisfy the demands. tion of the sun's apparent diameter of the geologists. To meet this difficould not be detected by the most re- culty Dr. Croll has advanced his “Imfined instruments of measurement. pact Theory,” which has been already Sir William Thomson has shown that considered in the paper referred to this shrinkage would amount to only (Gentleman's Magazine, June, 1891). thirty-five metres on the radius per The ancient philosopliers thought. annum, or one ten-thousandth of its that the sun miglt possibly be inhablength in two thousand years.

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Even in modern times this tity quite inappreciable.

hypothesis has been seriously considAccording to Helmholtz's theory, the ered. Dr. Elliott in 1787 upheld this suu's heat was originally generated by view, and on his trial at the Old Bailey the collision of two masses, as in Dr. for the murder of Miss Boydell his Croll's theory, but differing from that friends maintained his sanity and theory in the supposition that the quoted as proof of their assertiou the bodies approached each other under pages of his book in which this opiniou the effects of gravitation alone, and not was expressed. A necessary detail of with any initial velocity. In some Helmholtz's theory is that the sun books it is “paradoxically stated” that must be in a fluid state from its surface the sun is actually becoming hotter to its centre. Were this not so it would owing to condensation ; but this is soon grow dark, “as the conducting quite incorrect. As Sir William Thom- power of no kuown solid would suffice son points out, “ cooling and condensa- to maintain the incandescence.” The tion go on together." In fact, as the idea of a solid nucleus enclosed in a sun has been gradually losing heat for fiery envelope must, therefore, be abanages past, the amount of heat lost by doned and consigned to the limbo of all radiation must be in excess of that such uncritical theories. gained by shrinkage ; and, as this Sir William Thomson thus describes process is probably still in progress, the action which would probably take the sun must be actually cooling down. place during the formation of the sun Of course this cooling process is exces- according to the gravitation theory : sively slow — so slow, indeed, that one " Think of two cool solid globes, each estimate makes the maximum loss not of the same mean density as the earth, more than one degree Centigrade in avd of half the sun's diameter, given at seven years.

rest, or nearly at rest, at a distance According to Sir William Thomson, asunder equal to twice the earth’s disif the sun's heat could be maintained tance from the sun, they will fall toby shrinkage until twenty million times gether and collide in exactly half it the present annual expenditure is ra- year. The collision would last about diated away, the sun's diameter would half an hour, in the course of which be reduced to one-half what it is at they will be transformed into a violently present, and its density would be in- agitated incandescent fluid, mass, flying creased to about the specific gravity of outwards from the line of motion before lead. This would probably put a stop the collision, and swelling to : bulk to all further shrinkage, through several times greater than the sum of overcrowding of the molecules." the original bulks of the two globes.

Supposing the sun to have been radi- How far the Auid mass will fly out all ating out heat for the past fifteen mil- round from the line of collision it is lion years, the solar radius“ must have impossible to say. The motion is too been four times as great as at present.” complicated to be fully investigated by Sir William Thomson is not disposed to any kuown mathematical method. Å

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NEGRO COFFEL.

mathematician with sufficient patience | variables when near a maximum of might, however, approximate to the light indicate a great increase of leat, truth. . After a series of oscillations it which may possibly be due either to will subside, probably in the course of the collisions of thousands of meteortwo or three years, into a globular star ites or to solid bodies rendered incanof about the same dimensions, heat, descent by a “ violent grazing collisiou." and brightness as our present sun, but

J. ELLARD GORE. different from him in this, that it would have no rotation.

"If, however, each bad a transverse motion — in opposite directions of

From Chambers' Journal. 1.82 metres per second, the result would be a globe like our sun, rotating NEGRO or will coffee is the name in twenty-five days. If the trausverse that has been given to fedegozo seeds, velocity be anything more than 0.71 of on account of their being used in westa kilometre they would escape collision, ern tropical Africa and in some of the and would revolve in equal ellipses West India Islands by the natives as a round their centre of inertia in a period substitute for coffee. In some of the of one year, just grazing one another's French African colonies the seeds are surfaces every time they came round to also kuown as café nègre and café the nearest points of their orbits. If marron. Botanically, the plant producthe initial transverse velocity be less ing the seed is known as Cassia occidenthan, but not much less than, 0:71 of a talis. It grows very freely in most kilometre per second, there will be a tropical countries ; in fact, it is a comviolent grazing collision, and two bright mon weed, with a sickly, offensive suns, solid globes bathed in flaming smell, that many planters would fain fluid, will come into existence in the be rid of. The seeds are roasted and course of a few hours, and will com- ground, aud the infusion, made in the mence revolving round their common same way as ordinary coffee amazingly centre of inertia in long elliptic orbits resembles the finest Mocha. This fact in a period of little less than a year. is confirmed by Dr. Nicholls of DoTidal interaction between them will minica, who, writing to the director of diminish the eccentricity of their orbits, the Royal Botanic Gardens, Kew, a and, if continued long enough, will few years back, states : “I collected cause them to revolve in circular orbits some seeds, and directed my cook round their centre of inertia, with a to roast and grind them, so that I distance between their surfaces equal wight taste the coffee.' Other matters. to 6.44 diameters of each."

engaging my attention, I forgot the The bearing of the latter portion of circumstance until several days afterSir William Thomson's remarks on the wards, wher, one evening, my wife possible origin of binary stars will be inquired how I liked my after-dinner obvious to the reader. The “ violent cup of coffee. I turned to lier inquirgrazing collisions” in a period of about ingly, when she laughingly said : a year seem also to suggest a possible " That is your wild coffee.'

I was explanation of the nature of some of indeed surprised, for the coffee was the variable stars, of which the periods indistinguishable from that made of of several do not differ much from the best Arabian beans, and we in three hundred and sixty-five days. Dominica are celebrated for our good Indeed, this is the theory of variable coffee. Afterwards, some of the seeds, stars advanced by Professor Lockyer in roasted and ground, were brought to bis “Meteoric Hypotheses ; " but in me, and the aroma was equal to that this theory the l'evolving masses are of the coffee ordinarily used in the supposed to be swarms of meteorites, island.” and not solid bodies. The bright lines Dr. Livingstone took some of these observed in some of the long period I seeds to the Mauritius Botanical Gar

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dens, and mentioned that the natives / which he designated kola red (rouge of tropical Africa roasted and used de kola), and which a German scientist them like' coffee.

has since named kolanin. It has not been definitely stated that Besides using fedegozo seeds as the infusion has any stimulating effect, substitute for coffee, the natives embut it is only fair to suppose it has, ploy the whole plant as a remedial otherwise the negroes would hardly agent in various complaints and disemploy it in lieu of coffee. Chemical eases. It is closely allied to ordinary analysis shows it to consist of fatty senna in fact, in Liberia, on the west matters (olein and margarine), 4:9; coast of Africa, it is called small senna tannic acid, 0.9; sugar, 2:1 ; gum,

so readers will not be surprised to 28.8; starch, 2:0 ; cellulose, 34:0; learn that the whole plant is purgative. water, 7.0; calcium sulphate, and phos- This is mainly attributable to the muciphate, chrysophanic acid, 0.9; maliclaginous and extractive matters in acid, sodium chloride, magnesium sul- conjunction with the small percentage phate, iron, silica, together, 5.4 ; and of chrysophanic acid that analysis achrosine, 13:58 parts in one hundred. proves to be present in the plant. TorAchrosine is soluble in water, and com- refaction destroys the purgative prinmunicates to the latter à garnet color. ciple in the seeds and causes them to It contains carbon, hydrogen, oxygen, taste like coffee. nitrogen, and sulphur ; but its exact One of the most useful properties of composition has not been determined. the plant is its febrifuge action. It is It is soluble also in alcohol and in acids generally administered by boiling an and alkalies. The color cannot be fixed ounce of the seed in ten ounces of upon tissues by any known mordant, water; and when this quantity is l'eand it is this circumstance that induced duced to nine ounces, it is given to the Professor Clouet, who made the analy-patient during the cold period of sis, to term it achrosive, or “not color- rigor; a profuse perspiration follows, ing," although being colored itself. and the rigors do not recur. The seeds

If we might venture an hypothesis, have repeatedly been employed iu we would suggest that further investi- France and in some West India Islands gation into this coloring matter may for this purpose ; and instead of the prove that the color is the important decoction being used as just described, feature from an alimentary point of sixty grammes of the seed have been view. This has recently been proved macerated in a litre of Malaga wine. to be the case with kola. For many The value of the plant is recognized years scientists were puzzled as to the in all parts of the world. Mohammenature of the substance in the kola nut dan writers recommend its use in cases that produced the stimulating and nu- of coughs, especially whooping-coughs ; tritive effect. It was at first suggested an infusion of the root is considered by that it was due to caffeine ; but experi- the American Indians to be an antidote ments proved that this was not the against various poisons; and in Brazil

At length, after prolonged re- the same preparation is used as a tonic searches, Professor Heckel of Mar- and diuretic in dropsy and liver comseilles practically demonstrated that the plaints. This latter property has gained "muscle-bracing” and other beneficial for the plant the same unconventional properties of the kola nut were entirely title that country children apply to our due to the presence of a coloring body own dandelion.

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