American Chemical Journal, Volume 25Ira Remsen, Charles August Rouillu 1901 - Chemistry |
Contents
| 12 | |
| 54 | |
| 69 | |
| 77 | |
| 83 | |
| 89 | |
| 96 | |
| 111 | |
| 117 | |
| 123 | |
| 144 | |
| 156 | |
| 166 | |
| 172 | |
| 236 | |
| 284 | |
| 297 | |
| 303 | |
| 413 | |
| 419 | |
| 431 | |
| 437 | |
| 485 | |
| 496 | |
| 508 | |
| 517 | |
| 520 | |
Other editions - View all
Common terms and phrases
a-acid acetic action aldehyde alkaline amalgam ammonia ammonium analysis aniline aqueous barium benzene boiling boiling-point bromine cadmium cadmium iodide carbon atom cent Chem chloric acid chloride compound concentrated conductivity constituents contained cooling crystals decomposition dehydromucic acid determined dilute dissociating dissolved distillate double salt dried ester ether evaporated experiments filtered flask formation formed formula fraction freezing-point fuming sulphuric acid gave the following gram BaSO gram H₂O gram salt gram substance gave H Calculated heated hydrate hydrobromic acid hydrocarbon hydrochloric acid hydrogen insoluble iodide iodine ketone Liebig ligroin liquid melting melting-point mercury method mixture molecular weight molecule mucic acid nitrate nitric acid obtained oil gave ortho oxide oxygen perchloric acid peroxide phenol potassium praseodymium precipitate pure purified reaction recrystallized residue salt gave separated sodium solu soluble solution solvent specific gravity sulphate sulphonate sulphuric acid temperature tion triphenylchlormethane tube urea volume yield zinc μυ
Popular passages
Page 160 - The real density of the liquid is only one-fourteenth that of water, so that it is by far the lightest known liquid. This small density explains the rapidity with which the liquid is cleared on the entrance of the air snow. The relative smallness of the gas bubbles produced in the...
Page 163 - ... electric lamp. The light in this case coming through glass contains only, we may say, the visible spectra, so that the ultraviolet rays are not now essential. It is strange to find photographic action still relatively considerable. At the boiling point of liquid air the photographic intensity is reduced by 80 per cent of the value at the ordinary temperature. The photographic effect on a sensitive film immersed in liquid hydrogen as compared with the same placed in liquid air is as 1 to 2, so...
Page 161 - Geissler tube, previously exhausted to some 3 inches pressure, will, when the end part is immersed in liquid hydrogen, pass through all the well-known changes in the phases of striation — the glow on the poles, the phosphorescence of the glass — in the space of a fraction of a minute. From this it follows that theoretically we need not exhaust the air out of our double-walled vessel when liquid hydrogen has to be stored or collected.
Page 163 - The properties of the liquid we have witnessed in no way suggest the metallic character that chemists like Faraday, Dumas and Graham anticipated; and, for the future, hydrogen must be classed with the non-metallic elements. The liquefaction of hydrogen has been the consequence of some ten years' devotion to low temperature research. To many it may seem that the results have been indeed costly in more ways than one. The scientific worker who prepares the way for future development in this sort of...
Page 162 - If a closed vessel is full of hydrogen gas at atmospheric pressure, then, unlike the air vessels, it shows no condensation when a part of it is cooled in liquid hydrogen. To produce liquefaction we must increase the pressure of the gas, or reduce the boiling-point of the liquid hydrogen by exhaustion.
Page 162 - Among inorganic bodies the platinocyanide of ammonia is very remarkable in this respect, and generally the group in organic chemistry known as the ketonic bodies. In the case of bodies cooled in liquid hydrogen, it appears that some show phosphorescence by simple stimulation with the light coming from an ordinary carbon filament electric lamp.
Page 163 - The liquefaction of hydrogen has been the consequence of some ten years' devotion to low temperature research. To many it may seem that the results have been indeed costly in more ways than one. The scientific worker who prepares the way for future development in this sort of inquiry generally selects complicated methods, and is attracted or diverted into many by-paths of investigation. He may leave to his successors any credit that may be attached to cheapness and ease of production of the agent...
Page 161 - Leave a little mercury in the vessel containing air, just as if it had been left from making a mercurial vacuum. Now we know mercury, in such a vacuum, can easily be made to distil at the ordinary temperature when we cool a part of the vessel with liquid air, so that we should expect the mercury in the unexhausted test-tube to distil on to the surface cooled with the liquid hydrogen. This actually takes place. A rough comparison of the relative temperatures of boiling hydrogen and oxygen may be made...
Page 163 - ... so that 10 per cent, of the action at ordinary temperatures still remains. As every kind of chemical action so far examined is non-existent at this extreme temperature, these experiments suggest that the cause of the photographic action may be essentially physical. No better illustration could be given of the rapid diminution of chemical action at low temperatures than to remind you that fluorine gas, the most active elementary body, under such conditions, may be liquefied and kept in glass vessels....
Page 161 - ... which are noncondensable in this way of working, then the vacuum would not be so high as with pure oxygen or nitrogen. This method may be used to separate the incondensable gases from the air. Such air vacua when examined spectroscopically show the lines of hydrogen, helium, and neon. We may now employ this process to produce high vacua, and test their exhaustion by the character of the electric discharge. Vacuum tubes which have been prepared in this way show extraordinary resistance to the...