Vision Volatility

Viking Lander, 355 vinyl chloride, 764 virial coefficient, 168 virial equation, 168 viscosity, 186 visible light, 4, 6 vision, 113 vitamin, 74 vitamin C, F48 volatile, 310 volt, 492, A4 Volta, A., 483 voltage, 490 voltaic cell, 490 voltaic pile, 483... 

Like many volatile halocarbons and other hydrocarbons, inhalation exposure to carbon tetrachloride leads to rapid depression of the central nervous system. Because of its narcotic properties, carbon tetrachloride was used briefly as an anesthetic in humans, but its use was discontinued because it was less efficacious and more toxic than other anesthetics available (Hardin 1954 Stevens and Forster 1953). Depending on exposure levels, common signs of central nervous system effects include headache, giddiness, weakness, lethargy, and stupor (Cohen 1957 Stevens and Forster 1953 Stewart and Witts 1944). Effects on vision (restricted peripheral vision, amblyopia) have been observed in some cases (e.g., Johnstone 1948 Smyth et al. 1936 Wrtschafter 1933), but not in others (e.g., Stewart and Wtts 1944). In several fatal cases, microscopic examination of brain tissue taken at autopsy revealed focal areas of fatty degeneration and necrosis, usually associated with congestion of cerebral blood vessels (Ashe and Sailer 1942 Cohen 1957 Stevens and Forster 1953). 

This "outlandish creature was Mendeleeff, the Russian prophet to whom the world listened. Men went in search of the missing elements he described. In the bowels of the earth, in the flue dust of factories, in the waters of the oceans, and in every conceivable corner they hunted. Summers and winters rolled by while Mendeleeff kept preaching the truth of his visions. Then, in 1875, the first of the new elements he foretold was discovered. In a zinc ore mined in the Pyrenees, Lecoq de Roisbaudran came upon the hidden eka-aluminum. This Frenchman analyzed and reanalyzed the mineral and studied the new element m every possible way to make sure there was no error. Mendeleeff must indeed be a prophet For here was a metal exactly similar to his eka-aluminum. It yielded its secret of two new lines to the spectroscope, it was easily fusible, it could form alums, its chloride was volatile. Every one of these characteristics had been accurately foretold by the Russian. Lecoq named it gallium after the ancient name of his native country. 

In the medical community it is well known that humans exhale volatile metabolites which potentially carry important information about their health status. Thus, successful and fast detection of potential products of different metabohc processes becomes attractive, especially if the detection limits of the spectrometric methods used are low enough and the instruments become available at moderate price levels to be used as standard methods in hospitals or point-ofcare centers. The vision of the authors is to contribute to the use of human breath as a carrier of information of the health status of the body in addition to human blood and urine. 

Man is blessed with the sense of smell, taste, touch, vision, and hearing. Three of these senses (touch, vision, hearing) are referred to as the physical senses and are used for detection of mechanical, thermal, photic, and acoustic energy. The other two, the chemical senses, are used for the detection of volatile and soluble substances. The stimuli that excite the physical senses can be measured by both physical and psychophysical means. The volatile and soluble substances that excite the chemical senses can be defined but the stimuli caused by these substances can only be measured by psychophysical means.l z For all practical purposes these stimuli cannot be expressed as some unit of energy, instead they have to be expressed in the dimensions of quality, intensity, duration, and like and dis-1 ike. 

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