wells's principles and applications of chemistry; for the use of academies, high-schools, and colleges

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الصفحة 169 - ... them; and that these primitive particles being solids, are incomparably harder than any porous bodies compounded of them; even so very hard, as never to wear or break in pieces: no ordinary power being ' able to divide what God himself made One, in the first creation.
الصفحة 159 - A pound of the purest coal gives when burnt, sufficient heat to raise the temperature of 8086 pounds of water one degree of the centigrade thermometer; from this we can calculate that the magnitude of the chemical force of attraction between the particles of a pound of coal and the quantity of oxygen that corresponds to it is capable of lifting a weight of one hundred pounds to a height of twenty miles.
الصفحة 492 - The chemical force and the vital principle hold each other in such perfect equilibrium, that every disturbance, however trifling, or from whatever cause it may proceed, effects a change in the blood.
الصفحة 396 - Platinum exists in two states of minute subdivision, viz., as spongy platinum, and platinum black. The properties and preparation of spongy platinum have been already described (§§ 48, 296). Platinum black is the metal in a state of such fine subdivision, that it has the appearance of soot. It is easily prepared by slowly heating, to 212° F., with frequent agitation, a solution of chloride of platinum, to which an excess of carbonate of soda and a quantity of sugar have been added. The precipitated...
الصفحة 79 - From its extreme softness, its particles slide over each other in the act of expansion, and do not return to their original position. " A leaden pipe, used for conveying steam, permanently lengthens some inches in a short time, and the leaden flooring of a sink, which often receives hot water, becomes, in the course of use, thrown up into ridges and puckers.
الصفحة 386 - At a dull red heat this oxide is again decomposed into its constituents. Hydrochloric acid has little or no action on mercury, and the same may be said of sulphuric acid in a diluted state ; when the latter is concentrated and...
الصفحة 105 - ... and on the other hand, when a rise of temperature takes place, the thawing of the ice absorbs a like quantity of heat. Thus, in the one case, supplying heat to the atmosphere when the temperature falls, and in the other, absorbing heat from it, when the temperature rises.
الصفحة 492 - ... come in contact with any organ in the body, without yielding to its attraction. The slightest action of a chemical agent upon the blood exercises an injurious influence ; even the momentary contact with the air in the lungs, although effected through the medium of cells and membranes, alters the color and other qualities of the blood.
الصفحة 151 - No elementary substance can be an electrolyte : for from the nature of the process, compounds alone are susceptible of electrolysis. 2. Electrolysis occurs only whilst the body is in the liquid state. The free mobility of the particles which form the body undergoing decomposition is a necessary condition of electrolysis, since the operation is always attended by a transfer of the component particles of the electrolyte in opposite directions. Electrolysis is necessarily a process of electrical conduction,...
الصفحة 95 - ... point of a liquid will undergo a corresponding change. The pressure of the atmosphere at the level of the sea is about fifteen pounds upon each square inch of surface. It varies occasionally at the same place sufficiently to affect the boiling point to the extent of 4J degrees.

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