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angle animal appears atom Aurora Borealis axis Barlow basalt bodies carbonic acid cavities centre colour common contains coruscations crystals decomposed dense fluid diameter direction distance Edinburgh effect equal expansible fluid experiments extremity feet flame force greywacke heat horizon hyaenas hydrosulphuric acid inches instrument iron Journal July Klaproth lava light magnetic mean temp mean temperature mercury metal mineral motion muriatic acid nature nearly needle nimbi nitric acid observations obtained oxide paper pass Perihelion phenomena Pholades phosphoric acid Pictet pitchpipe plate pole portion position potash produced Professor Hansteen quantity rain rays refraction remarkable right ascension river rocks round seen side similar slate species specimen substance sulphate sulphuret sulphuric acid sunrise supposed surface tained thermometer tion topaz tube tufa vacuity vapour vibrations volcanic weight whole wind yellow
Pàgina 81 - The flame of sulphur and nitre contains a red ray which appears to me of a remarkable nature. This red ray appears to possess a definite refrangibility, and to be characteristic of the salts of potash, as the yellow ray is of the salts of soda, although, from its feeble illuminating power, it is only to be detected with a prism.
Pàgina 245 - FRSE Lecturer on Chemistry, and Fellow of the Royal College of Physicians, Edinburgh. AN the paper which I had the honour of reading before the Society at its last meeting, on the detection of lithia in minerals, • Read before the Royal Society of Edinburgh on the 19th December 1825.
Pàgina 80 - ... presence of the substance, which suffers no diminution in consequence. Thus a particle of muriate of lime on the wick of a spirit-lamp will produce a quantity of red and green rays for a whole evening without being itself
Pàgina 369 - The direction of the magnetic polarity of small needles exposed to an electric current directed along a wire stretched longitudinally, varies with the distance of the wire :"—the action being found to be periodical with the distance. M. Savary observed three periods, and also the fact that the distances of maximum effect and of the nodal zeros " vary with the length and diameter of the wire, and with the intensity of the discharge.
Pàgina 81 - For instance, the orange ray may be the effect of the strontia, since Mr Herschel found in the flame of muriate of strontia a ray of that colour. * If this opinion should be correct and applicable to the other definite rays, a glance at the prismatic spectrum of a flame may show it to contain substances, which it would otherwise require a laborious chemical analysis to detect.
Pàgina 189 - There is a continual discharge of carbonated hydrogen gas from the well ; and also from the bed of the creek on which the well is situated, at various places for the distance of half a mile. This gas is highly inflammable, and where there is a free discharge of it, it will take fire on the surface of the water, on the application of a lighted stick, or the flash of a gun, and continue burning for days, unless put out by a heavy shower or a high wind. It was this discharge of gas that induced the...
Pàgina 349 - ... small balls. The mouth of the pot being stopped up, it is then put into the furnace, and as soon as the materials have sunk, more of the same mixture must be put in, till the pot is filled with a melted vitreous substance, and a strong fire must be kept up to have the mass completely fused, and as soon as possible. When the fumes diminish, small portions must be taken out, to see if the glass is sufficiently refined, which generally happens in about 22 hours. The glass is then fit for use, and...
Pàgina 152 - The latter principally, and in some instances almost entirely, consist of broken greywacke, slate, and sandstone, more or less affected by heat, and pulverized. It is probably owing to the clayey nature of these fragments, when reduced to great fineness, that the craters of this country have nearly, without exception, become reservoirs of water, or Maare, as they are called by the natives. Most of them still have small lakes or peatmarshes at their bottom. Some have been drained for the sake of cultivation...
Pàgina 86 - ... as to form a white bow, the red, which projects beyond the rest, being always broadest, so that if all the stripes be supposed to expand, while they preserve their comparative magnitude, the middle of the red may coincide with the middle of the blue ; and it will appear, on calculation, that a white bow will be formed a few degrees within the usual place of the coloured bow, when the drops are about ^0 or ^i of an inch in diameter.
Pàgina 158 - The bottom of this cavity is occupied by water to about a third of its superficial extent ; the remainder is a plain, on which the village of Meerfeld is seated. The most southerly point of this district, on which volcanic products have been met with, is the vicinity of the baths of Bertrich, a village seated at the bottom of the deep and narrow mountain gorge of the river Isbach, which flows at the distance of a few miles into the Moselle. Here a lava, which has congealed into an exceedingly hard,...