atmosphere muft needs extend much further than any poffible actually visible appearance of it, by means of the luminous difk; and must be diminishing continually in denfity. But however far it may extend, and whatever its denfity, or rarity, may be beyond that luminous difk of intenfe light, which we have been confidering; it could, upon optical principles, be feen no further than that luminous disk extends; any more than a Star, in the neighbourhood of the Sun at noon-day, or than the Moon at the new. Although, however, fuch luminous difk must be the visible boundary of the Sun's appearance, and of the appearance of the Sun's atmosphere;-yet on account of different refractions occafioned in that atmosphere, by the different denfities of different parts, the furface of fuch difk muft appear broken, and uneven, as with little knobs :-occafioning, indeed, exactly fuch appearances of little elevations, as Dr. Herfchel mentions;-and fuch a general appearance of the whole furface as he defcribes, as being like the roughness of the coat of an orange *Philof. Tranf, for 1795, p. 56; and fee alfo the Rev. Mr. Wollafton of Chislehurst's account, Philofoph. Tranf. Vol. LXIV. p. 339. Dr. Dr. Herschel, after the whole of his curious obfervations on the Solar Disk, forms nearly the fame kind of conclufions that I had before formed, concerning the body of the Sun not being fo large as it appears when measured by its prefent vifible difk+; and concerning heat being not in the folar rays themselves, but in the bodies heated ‡ :—and he forms thefe latter conclufions from fome of those very kind of experiments, which I had also referred to.-And he then concludes the Sun to be an inhabitable world §. He rejects, however, with fome degree of afperity, the fuppofition of the Sun's being the abode of Bleed Spirits; forgetting the poffibility of Spirits being clothed with glorified bodies; and forgetting that OUR LORD Himfelf, after his rifing from the dead, took fingular pains to convince the difciples that he had a real tangible body, of as actual * These conclufions were publifhed in the first edition of the Morfels of Criticifm, in January 1788, when I fent my book to Dr. Herfchel; and his curious Obfervations were communicated to the Royal Society in 1794, and published in the Philofophical Tranfactions for 1795, P. 46. + Phil. Tranf. for 1795, p. 50. 54. 57. 62. § Ibid. p. 63. Ibid. p. 64. folid fubftance as the common human frame itself. 14. Let us take, however, the conclufion fimply, in Dr. Herfchel's own way;that the Sun is an inhabitable world;—whether its inhabitants be Bleffed Spirits, in glorified bodies, or of any other clafs:—yet still, (to proceed with the confideration of the optical effect of rays proceeding from the Sun,) it may be added, confiftently with what I published so many years ago ;-that, whether they be bodies feen by emitted light,-(as Angels are, in so many inftances, faid to have appeared, in Holy Scripture, and as OUR LORD Ilimfelf appeared, during his tranffiguration on the Mount,)-and that light so emitted from all manner of bodies on the Sun, be, in reality, its rays;-or whether they be bodies illuminated only, according to Doctor Herfchel's hypothefis, by the luminous beams of aurora fhining in the folar atmosphere ;cither way, (on the trueft philofophical, and optical principles,) the whole effect of those luminous rays reaching to our earth, must be juft fuch as that of our funshine really is. For let (SS), Fig. 8, be the body of the Sun ; and fuppofe various objects (abcdefghikl mnop) of different colours, to exit on different parts of its furface; whatever they may refemble; whether plants, or animals, or buildings, or embodied inhabitants, or mountains, or rocks, or rivers, or feas; and however large, or however minute, they may all or any of them be-fuppofe them to adorn its whole orb, and to fend rays of light from thence; either emitted light from themfelves; or light reflected from Aurora in the Sun's luminous atmosphere (AAA):-in either cafe, the whole congregated pencil of rays that reach any eye, from thence, (though fome may be red from (a), or blue from (b), or yellow from (c), or green from (d), or orange from (e), or indigo from (f), or violet from (g), or purple from (h), or of any other intermediate mixed colours ;) yet ftill the whole congregated pencil of rays, of fo many different colours, from fo many different parts, coming from the whole difk, muft at laft reach any eye, whereever placed, mixed all together, in one pencil of rays, as is fhewn at (E) :—and the whole pencil will now confift of all thofe different colours combined, and blended together, and forming only a whitish, or yellowish appear ance; ance; which, on the body of the Sun itself, had exhibited a vaft variety of differently coloured appearances, of various forms, on its whole furface. 15. Now then, let this pencil of rays, (which, on account of the Sun's immenfe diftance, comes to our eyes nearly as if they were all parallel,) be received on a prism; and what is the well known effect?—why plainly, on account of the different refrangibility of rays of different colours, that whencefoever they individually came, or how near together, or how far off foever, any of the different kinds of them, on their first coming from the body of the Sun might be; that yet thefe rays, from what parts of the Sun foever any of those of each feparate primævaf colour might come, will all at last be feparated, by the prifm, exactly according to the precife power of refrangibility of the rays of each refpective colour; and therefore, confistently moft exactly with all the Newtonian experiments, will only form a longish fpectrum of the Sun, of the feven primæval colours in fucceffive order; wherein each feparate primæval colour will appear bright, jaft according |