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The Biosphere: Environmental Biochemistry
Published in Stanley Manahan, Environmental Chemistry, 2017
Waxes are produced by both plants and animals, largely as protective coatings. Waxes are found in a number of common products such as lanolin in sheep’s wool and cetyl palmitate (below) in the spermaceti wax extracted from the blubber of the sperm whale and used in some cosmetics and pharmaceutical preparations.
The Biosphere
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Waxes are produced by both plants and animals, largely as protective coatings. Waxes are found in a number of common products such as lanolin in sheep's wool and cetyl palmitate (below) in the spermaceti wax extracted from the blubber of the sperm whale and used in some cosmetics and pharmaceutical preparations.
Coal-Gas
Published in Robert Routledge, Discoveries and Inventions of the Ninteenth Century, 2018
The illuminating power of coal-gas may be measured directly, by comparing the intensity of the light emitted by a gas-flame consuming a known quantity of gas per hour with the light yielded by some standard source. The standard usually employed is a spermaceti candle burning at the rate of 120 grains of sperm per hour. It is not necessary that the candle actually used should consume exactly this amount, but the consumption of sperm by the candle during the course of each experiment is ascertained by the loss of weight, and the results obtained are easily reduced to the standard of 120 grains per hour. • An instrument is used for determining the relative intensities of the illumination, called Bunsen’s photometer. It consists of a graduated rule, or bar of wood or metal, about 10 ft. long. At one end of this bar is placed the standard candle, at the other is the gas-flame. A stand slides along the rule supporting a circular paper screen at the level of the two flames, and at right angles to the line joining them. This paper screen is made of thin writing-paper, which has been brushed over with a solution of spermaceti, except a spot in the centre, or, more simply, a grease-spot is made in the middle of a piece of paper. In consequence the paper surrounding the spot is much more transparent; yet when it is placed so that both sides are equally illuminated, a spectator will not perceive the spot in the centre when viewing the screen on either side. When the screen has been placed by trial in such a position between the two sources of light, it is only necessary to measure its distance from each flame in order to compute the number of times the illuminating power of the gas-flame exceeds that of the candle. This computation is based on the fact that the intensity of the light from any source diminishes as the square of the distance from the source. Thus, if a sheet of paper be illuminated by a candle at 2 ft. distance, it will receive only one-fourth of the light that would fall upon it were its distance but 1 ft, and if removed to 3 ft. distance it has only one-ninth of the light. In the instrument used for measuring the illuminating power of gas the rule is graduated in accordance with this law, so that the relative intensities may be read off at once. The gas passes through a meter for measuring accurately the quantity per minute which is consumed by the burner, and there is also a gauge for ascertaining the pressure. Another mode of estimating the illuminating power of coal-gas is by determining the quantity of carbon contained in a given volume. For, in general, the richness of the gas in carbon is a fair index of the quantity of its luminiferous constituents. This may be readily effected by exploding the gas with oxygen, and measuring the amount of carbonic acid produced. Still more accurate determinations of the illuminating value of gas may be obtained by a detailed chemical analysis.
Illuminating the streets, alleys, parks and suburbs of the American City: non-networked technologies, 1870-1920
Published in History and Technology, 2020
The first street lights installed by many American cities burned whale oil in stand-alone lamps, usually derived from the blubber of the artic right whale or spermaceti found in the heads of sperm whales. Lamplighters both ignited and serviced them, keeping reservoirs full.8 Beginning in the first quarter of the century, however, street lights that consumed gas from piped networks connected to manufacturing gas plants (MGPs) began to replace them. The origins of this lighting rested on research in Great Britain and Europe in the late eighteenth and early nineteenth centuries. These gas networks, as Leslie Tomory has written, were modeled on London’s earlier integrated water system that provided the inspiration for numerous other urban networks.9 The MGPs originally used a variety of organic substances to generate gas, but over time bituminous coal became the primary feedstock for gas production.10 Networked lamps consuming coal gas gradually replaced stand-alone whale oil lamps as the most common form of American street lighting. As Christopher F. Jones observes, this reflected an important part of the shift from an organic to a mineral regime.11