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Pàgina iii - Report on the geology of the Lake Superior land district : by JW Foster and JD Whitney, United States Geologists. Part II.
Pàgina 379 - In the chick no traces of the kidney are perceptible, according to my own observations, until the end of the fourth or the beginning of the fifth day. The ureter, then, is the part first seen, and consists of a simple tube, the upper part of which sends off branches.
Pàgina 452 - Outlines of a Mechanical Theory of Storms, containing the true [?] law of lunar influence, with practical...
Pàgina 175 - As these soundings are believed to be the deepest ever submitted to microscopic examination, and were obtained at localities far remote from those previously noticed, they were studied very carefully, and the following are the facts ascertained : — 1. None of these soundings contain a particle of gravel, sand, or other recognizable unorganized mineral matter. 2. They all agree in being almost entirely made up of the calcareous shells of minute, or microscopic...
Pàgina 62 - When these germs have reached the size of 30^th of an inch in diameter, there appears on each, near one end, a yellowish vitelluslooking mass or spot, which is composed of large yellowish cells, which in size and general aspect are different from those constituting the germ proper. This yellow mass increases part passu with the germ, and at last lies like a cloud over and concealing one of its poles.
Pàgina 136 - Schyf, or mill, which revolves from two thousand to three thousand times per minute. The diamond is fixed in a ball of pewter at the end of an arm, resting upon the table in which the plate revolves ; the other end, at which the ball containing the diamond is fixed, is pressed upon the wheel by moveable weights at the discretion of the workman.
Pàgina 74 - Aphides cannot be said to constitute as many true generations any more than the different branches of a tree can be said to constitute as many trees; on the other hand, the whole suite from the first to the last constitute but a single true generation.
Pàgina 22 - Murchison and de Verneuil,* that the lowest beds in Scandinavia, containing the least traces of organic life, are the exact equivalents of the Lower Silurian strata of the British Isles, and that these have been distinctly formed out of, and rest upon, slaty and other rocks which had undergone crystallization before their particles were ground up and cemented together again to compose the earliest beds in which organic life is traceable. To this most ancient system of rocks in Scandinavia, they have...
Pàgina 220 - ... from this reasoning, that if we throw a greater quantity of light upon an object, so that more may be collected by the object-glass, we shall be the better able to define its structure ; which would probably be the case if the additional light could be thrown only upon those minute parts which we wish to examine, and not upon the whole object. But as we cannot do this — as the increase of illumination cannot be made to increase the relative proportions of light which proceed from these minute...