Another question remains, that with respect to the galaxy, whether the galaxy be a collection of the smallest of the stars, or a combined body and region of the ether of an intermediate substance between that of the ether and the stars. For that theory about exhalations has itself now long exhaled, not without fixing a brand on Aristotle's genius, who had the audacity to put forth such a figment, fastening upon a thing so invariable and fixed, an evanescent and fluctuating character. But an end to this question as proposed by us, seems to be easily attainable, if we are to give credit to the accounts of Galileo, who has arranged that confused luminous appearance into numbered and mapped constellations. For, that the galaxy does not prevent the visibility of those stars which are found within its limits, is not enough to settle the question, nor to incline the matter either way. It only refutes, perhaps, the notion that the galaxy is placed lower than the part of ether containing the stars; for, if this were the case, and the continuous body had also some depth of itself, it is consistent with reason to suppose that our vision would be prevented. And, if it were placed at the same altitude as the stars which are visible in it, there is no reason why stars should not be scattered about in the galaxy itself, not less than in the rest of the ether. Thus we have treated of this question. These six questions, then, refer to the substance of the heavenly bodies; what, namely, is the substance of heaven in general, what of the interstellar air, what of the galaxy, and what of the stars themselves, whether compared with one another, or with our fire, or with their own essence?

But, with respect to the number, magnitude, configuration, and remoteness of the stars, with the exception of the phenomena and historical inquiries, of which we shall speak by-and-by, the problems which philosophy offers are generally simple. With respect to their number, too, there follows another question: whether that be the true number of the stars which is visible, and which has been set down and described by the labours of Hipparchus, and comprised within the plan of the celestial globe. For it is but a barren reason which is assigned for the incalculable number of stars, usually hid, and, as it were, imperceptible, which are commonly seen in winter, particularly in clear nights, namely, that these appearances are not smaller stars, but emanations, scintillæ,

host of heaven, by Galileo, not only in that cohort which is distinguished by the name of the milky way, but also amidst the stations and system of the planets. Now, stars become imperceptible either on account of the minuteness of their size, or their capacity, (the term tenuity we do not much approve of, since pure flame is a body of the most subtle tenuity,) or on account of their remoteness and distance. The question with respect to the superflux of stars, created by the production of new ones, we refer to the part which treats of comets.

As regards the magnitude of the stars, the visible magnitude belongs to the general phenomena, the real to the philosophical inquiry comprehended only in our twelfth problem: what are the real dimensions of each star, either discovered by measurement, or, if not, by comparison? for it is easier to discover and demonstrate that the globe of the moon is less than the globe of earth, than that the globe of the moon is a mile round. We must, then, use all trial and exertion to ascertain their exact dimensions; if these cannot be had, we must make use of their comparative.

Now, the magnitudes of the stars are either taken and inferred from their eclipses and obscurations, or from the bounds to which they extend their light, and the other properties which each of these bodies, in proportion to their magnitude, emit and propagate; or, lastly, by the harmony of the universe, which confines and limits, by a certain necessity, the parts of the homogeneous bodies. For we must not rest upon the accounts given by astronomers of the bare magnitude of the stars, (though they have laboured in that attempt, seemingly with great and exact minuteness, yet in reality with no little license and temerity;) but must seek, if any present themselves, proofs and evidence more to be trusted to and more genuine. Now, the magnitude and distance of the stars reciprocally indicate each other by the methods of opics: the roots of which science, however, ought to be a little shaken.

The question of the true magnitude of the stars is the twelfth in our enumeration: there follows another respecting the form, whether they be globes, that is, masses of matter of a solid round figure? Now, there are apparently three figures of the stars; spherical and comose, as the sun; spherical and angular, as the stars, (the coma and angles relate here only to aspect, the spherical form only to substance;) spherical only, as the moon. For, no star looks oblong, or triangular, or square, or of any other figure than the above. And, it appears to be the order of nature that the larger accumulations of things, for their own preservation and a truer union of parts, impact themselves into globes.