Really, said the Marchioness, with an air of deep reflection and astonishment, all this is managed with wonderful order; nature had certainly in these instances a view to the wants of living beings; this admirable disposition of light was not the effect of chance. Only the planets which are distant from the sun have been provided with moons--the Earth, Jupiter, and Saturn; for Venus did not require any; nor Mercury who already has too much light; whose nights are extremely short, and probably considered a greater blessing than even the days. But stop--I think Mars, who is farther from the sun than we, is without a moon. We cannot conceal the fact, I replied; he has none; but he doubtless has resources for the night which we are ignorant of. You have seen phosphorus; matters of that kind, whether liquid or dry, receive and imbibe the light from the sun, which they emit with some force when in the dark. Mars perhaps has high rocks of phosphorus that absorb, in the day-time, light enough to irradiate the night. You must own it would be an agreeable sight for the rocks to light up as soon as the sun was set, and without art, produce the most magnificent illuminations, that with all their radiance, would not have the inconvenience of casting any heat. In America, you know, there are birds which in the dark will afford light enough to read by: how can we tell whether Mars has not a great number of such birds, who, as soon as the night is come, disperse themselves on every side, and give an artificial day? I am not satisfied, answered she, either with your rocks or birds. They would be pretty enough to be sure; but as nature has bestowed so many moons on Saturn and Jupiter, it shews that moons are necessary. I should have been very much pleased to find that all the worlds at a great distance from the sun had some, if Mars had not formed a disagreeable exception. Ah! replied I, if you were more deeply versed in philosophy you must accustom yourself to see exceptions to the best systems. We clearly see that some things are adapted in the most perfect manner to their end; others we accommodate as well as we can, or perhaps are obliged to content ourselves with knowing nothing about them. Let us do so with respect to Mars, since our researches are fruitless, and resolve to say no more about him.