The circle of the sciences: a series of treatises on the principles of science : with their application to practical pursuits, المجلد 1

الغلاف الأمامي
R. Griffin and Company, 1860

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الصفحة 41 - ... 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 65 - Hot liquids, generally speaking, are more powerful solvents than cold ones To four ounce-measures of water, at the temperature of the atmosphere, add three ounces of sulphate of soda in powder. Only part of the salt will be dissolved, even after being agitated some time. Apply heat, and the whole of the salt will disappear. When the liquor cools, a portion of salt will separate again in a regular form, or in crystals. This last appearance affords an instance of erystallization.
الصفحة 66 - Spread thinly, on a piece of tinfoil, thres or four inches square, some dry nitrate of copper*, and wrap it up. No effect will follow. Unfold the tinfoil, and having sprinkled the nitrate of copper with the smallest possible quantity of water, wrap the tinfoil up again as quickly as possible, pressing down the edge closely.
الصفحة 13 - Attraction is a property which is common to a great variety of bodies. It is most strongly exerted in solids, and in these it is proportionate to the mechanical force required for effecting their disunion. In liquids, it acts with considerably less energy ; and in aeriform bodies we have no evidence that it exists at all ; for their particles, as will afterwards be shown, are mutually repulsive, and, if not held together by pressure, separate
الصفحة 51 - Geoffroy, a French chemist. The substance, whose affinities are to be expressed, is placed at the head of a column, and is separated from the rest by a horizontal line. Beneath this line are arranged the bodies, with which it is capable of combining, in the order of their respective forces of affinity ; the substance which it attracts most strongly being placed nearest to it, and that, for which it has the least affinity, at the bottom of the column.
الصفحة 66 - ... done by the action of the mouth. The finger is then pressed on the upper orifice of the tube ; and the lower orifice being brought to the bottom of the vessel containing the liquid, the finger is withdrawn, and the liquid descends from the tube, without mingling with the upper stratum. When a solution of carbonate of potassa is thus separated from diluted sulphuric acid, for which it has a powerful affinity, by the intervention of a thin stratum of brine, the two fluids will remain distinct and...
الصفحة 31 - ... concomitant of chemical action. In some cases brilliant colours are destroyed, as when chlorine is made to act on solution of indigo. In other instances two substances, which are nearly colourless, form, by their union, a compound distinguished by beauty of colour, as when liquid potassa is added to very dilute syrup of violets. Certain colours appear also to belong essentially to chemical compounds, and to be characteristic of them. Thus 100 parts of quicksilver, and 4 of oxygen, invariably...
الصفحة 45 - ... proportions merely, without regard to other considerations. On this subject Dr. Dalton, in the second part of his New System, recently published, has made the following remarks : — " When two bodies, A and B, combine in multiple proportions ; for instance, when 10 parts of A combine with 7 of B to form one compound, and with 14 to form another, we are directed by some authors to take the smallest combining proportion of one body, as representative of the elementary particle or atom of that...
الصفحة 59 - B has an affinity for a farther portion of one of its ingredients. If then C be brought into contact with the compound AB, we may have, acting at the same moment, the affinity of C for A, which partly decomposes the compound AB ; and the affinity of the undecomposed part of AB, for that portion of B which is set at liberty.
الصفحة 55 - ... remains in solution. If both the bodies had remained in solution, they would both have been placed above the upper line ; or, if both had been precipitated, beneath the lower one. If either one or both had escaped in a volatile form, this would have been expressed by placing the volatilized...

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