MESSRS EDITORS—On page 183 of the current volume of the SCIENTIFIC AMERICAN, is an article under the head "Moonology," about which volumes of the most wild speculations might be collected It is truly astonishing to notice the almost universal prevalence of the superstitious notions with regard to such things And so long as scientific men encourage such things, by sending forth to the world thousands upon thousands of almanacs, containing different "weather signs," just so long will the mass of mankind be subject to such superstition As I have never seen or heard any arguments, except those of a speculative kind, in 'avor of regarding the moon's phases, as peculiarly favorable to planting, laying fences, spreading manure, and a thousand other et ceteras, I must regard the whole as an offspring of superstition and speculative philosophy Last spring I planted my potatoes in the " new" of the moon, (the unfavorable time,) but at digging time I had an excellent crop, rather superior to any in the neighborhood, both as to size and number of bushels, according to the quantity of ground I had firstrate 5oil, and then tended them well Both the sun and moon, undoubtedly, exBrcise an influence on our atmosphere, through attraction, in the growth of vegetation, and in producing chemical changes which cause wind, rain, hail, amp;c ; but the peculiar position or phase of the moon, with regard to the time of planting only, can have no such influence whatever Now, as a matter of curiosity and question, if we put a potato in a cellar which has but me window, and if the cellar be sufficiently warm, the potato will sprout, and the leading pine will run directly towards the window, especially if it (the window) be very small The vine will run along the floor of the cellar until it reaches a point where a direct ray of light through the window could not reach it ; it will then raise its head, and still aim directly for the window, and will continue to grow in that direction, as long as it can support itself Will some one explain this upon natural principles ? E PERIN Blue Grass, Iowa, March, 1858 [Animals have certain constitutional qualities which we term instinct, and so have plants, although the two are different in their character What is it, then, but vegetable instinct, which makes the potato vine seek the light in a cellar ?—the same law which makes the roots of bushes and trees strike into the soil in the direction of a stream, or where they can obtain moisture, for nourishment Light is as essential to the life and vigor of a plant as moisture Many persons suppose that most of the almanacs published are edited by men of science; this is not the case ; and those referred to by our correspondent are certainly not the productions of scientific men—EDS