Very likely, since one or two have done so within a recent period.  What will be the effect?  That depends on circumstances.  There is good reason to suppose we passed through the tail of a comet in 1861, and the only [Page 134] observable effect was a peculiar phosphorescent mist.  If the comet were composed of small meteoric masses a brilliant shower would be the result.  But if we fairly encountered a nucleus of any considerable mass and solidity, the result would be far more serious.  The mass of Donati’s comet has been estimated by M. Faye to be 1/20000 of that of the earth.  If this amount of matter were dense as water, it would make a globe five hundred miles in diameter; and if as dense as Professor Peirce proved the nucleus of this comet to be, its impact with the earth would develop heat enough to melt and vaporize the hardest rocks.  Happily there is little fear of this:  as Professor Newcomb says, “So small is the earth in comparison with celestial space, that if one were to shut his eyes and fire at random in the air, the chance of bringing down a bird would be better than that of a comet of any kind striking the earth.”  Besides, we are not living under a government of chance, but under that of an Almighty Father, who upholdeth all things by the word of his power; and no world can come to ruin till he sees that it is best.

[Page 135] VIII.

THE PLANETS AS INDIVIDUALS.

“Through faith we understand that the worlds [plural] were framed by the word of God, so that things which were seen were not made of things which do appear.”—­Heb. xi. 3.

[Page 136] “O rich and various man!  Thou palace of sight and sound, carrying in thy senses the morning, and the night, and the unfathomable galaxy; in thy brain the geometry of the city of God; in thy heart the power of love, and the realms of right and wrong.  An individual man is a fruit which it costs all the foregoing ages to form and ripen.  He is strong, not to do but to live; not in his arms, but in his heart; not as an agent, but as a fact.”—­EMERSON.

[Page 137] VII.

THE PLANETS AS INDIVIDUALS.

How many bodies there may be revolving about the sun we have no means to determine or arithmetic to express.  When the new star of the American Republic appeared, there were but six planets discovered.  Since then three regions of the solar system have been explored with wonderful success.  The outlying realms beyond Saturn yielded the planet Uranus in 1781, and Neptune in 1846.  The middle region between Jupiter and Mars yielded the little planetoid Ceres in 1801, Pallas in 1802, and one hundred and ninety others since.  The inner region between Mercury and the sun is of necessity full of small meteoric bodies; the question is, are there any bodies large enough to be seen?

The same great genius of Leverrier that gave us Neptune from the observed perturbations of Uranus, pointed out perturbations in Mercury that necessitated either a planet or a group of planetoids between Mercury and the sun.  Theoretical astronomers, aided by the fact that no planet had certainly been seen, and that all asserted discoveries of one had been by inexperienced observers, inclined to the belief in a group, or that the disturbance was caused by the matter reflecting the zodiacal light.