Necessary to determine the specific gravities of the various gases referred to some one of them, say hydrogen; the numbers so obtained giving the weights of the molecules referred to that of the hydrogen molecule.
The following table gives the specific gravities of many metals.
Buchanan on the " Challenger " it has been usual for British investigators to calculate specific gravities for sea-water at 60° F.
Buchan, " Specific Gravities and Oceanic Circulation," Trans.
With all the important work he accomplished in physics - the enunciation of Boyle's law, the discovery of the part taken by air in the propagation of sound, and investigations on the expansive force of freezing water, on specific gravities and refractive powers, on crystals, on electricity, on colour, on hydrostatics, &c. - chemistry was his peculiar and favourite study.
Specific gravity bottles are also adjusted at 60° F., the figures indicating specific gravities being quotients obtained by dividing in each instance the weight of the solid or liquid by the weight of an equal bulk of water, both taken at 60 F.
In 1815 he published anonymously in the Annals of Philosophy a paper "On the relation between the specific gravities of bodies in their gaseous state and the weights of their atoms," in which he calculated that the atomic weights of a number of the elements are multiples of that of hydrogen; and in a second paper published in the same periodical the following year he suggested that the rrpcbrn iiXrl of the ancients is realized in hydrogen, from which the other elements are formed by some process of condensation or grouping.
Represents "a small glass instrument for estimating the specific gravities of liquors," an account of which was promised by Boyle in the following number of the Phil.
Emerges to B), when a brass weight such as C has been screwed on to the bottom at There are a great many such weights, of different sizes, and marked to be screwed on instead of C, for liquors that differ more than nth from proof, so as to serve for the specific gravities in all such proportions as relate to the mixture of spirituous liquors, in all the variety made use of in trade.
There are also other balls for showing the specific gravities quite to common water, which make the instrument perfect in its kind."
Clarke's hydrometer, as afterwards constructed for the purposes of the excise, was provided with thirty-two weights to adapt it to spirits of different specific gravities, and eleven smaller weights, or "weather weights" as they were called, which were attached to the instrument in order to correct for variations of temperature.
Desaguliers himself constructed a hydrometer of the ordinary type for comparing the specific gravities of different kinds of water (Desaguliers's Experimental Philosophy, ii.
Adie's sliding hydrometer is of the ordinary form, but can be adjusted for liquids of widely differing specific gravities by drawing out a sliding tube, thus changing the volume of the hydrometer while its weight remains constant.
He also replaced the letters on the stem by the corresponding specific gravities referred to water as unity.
Further information concerning these instruments and the state of hydrometry in 1803 will be found in Atkins's pamphlet On the Relation between the Specific Gravities and the Strength of Spirituous Liquors (1803); or Phil.
The following table gives the specific gravities corresponding to the principal graduations on Sikes's hydrometer at 60° F.
When loaded with either of the lightest two weights the instrument is specifically lighter than Sikes's hydrometer when unloaded, and it may thus be used for specific gravities as low as that of absolute alcohol.
The marine hydrometers, as supplied by the British government to the royal navy and the merchant marine, are glass instruments with slender stems, and generally serve to indicate specific gravities from 1.000 to 1.040.
The advantage of keeping the solution in motion is due partly to the renewal of solution thus effected in the neighbourhood of the electrodes, and partly to the neutralization of the tendency of liquids undergoing electrolysis to separate into layers, due to the different specific gravities of the solutions flowing from the opposing electrodes.
The specific gravities of oils and fats vary between the limits of o-910 and 0.975.
The specific gravities of most non-drying oils lie between 0.916 and 0.920, and of most semi-drying oil y between 0.920 and 0.925, whereas the drying oils have specific gravities of about 0.930.
The animal and vegetable fats possess somewhat higher specific gravities, up to 0.930.
In his Discorso intorno alle cose the stanno su l'acqua, published in 1612, he used the principle of virtual velocities to demonstrate the more important theorems of hydrostatics, deducing from it the equilibrium of fluid in a siphon, and proved against the Aristotelians that the floating of solid bodies in a liquid depends not upon their form, but upon their specific gravities relative to such liquid.
The fundamental objections to oil gas for the enrichment of coal gas are, first, that its manufacture is a slow process, requiring as much plant and space for retorting as coal gas; and, secondly, that although on a small scale it can be made to mix perfectly with coal gas and water gas, great difficulties are found in doing this on the large scale, because in spite of the fact that theoretically gases of such widely different specific gravities ought to form a perfect mixture by diffusion, layering of the gas is very apt to take place in the holder, and thus there is an increased liability to wide variations in the illuminating value of the gas sent out.
For this correction an exact knowledge of the specific gravities of the metals under comparison is required.