Volume 1

Cooley's Cyclopædia of practical receipts and collateral information in the arts, manufactures, professions, and trades, including medicine, pharmacy, and domestic economy : designed as a comprehensive supplement to the pharmacopœia and general book of reference for the manufacturer, tradesman, amateur, and heads of families.

  • Cooley, Arnold J. (Arnold James)
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Cooley's Cyclopædia of practical receipts and collateral information in the arts, manufactures, professions, and trades, including medicine, pharmacy, and domestic economy : designed as a comprehensive supplement to the pharmacopœia and general book of reference for the manufacturer, tradesman, amateur, and heads of families. Source: Wellcome Collection.

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    but not long enough to discolour it. It may be tinged of various shades by the addition of the proper ' stains.' ID'RIALIN. (VLjgO. A fusible, inflam- mable substance, found associated with the native cinnabar of the mines of Idria, in Carniola. It is extracted from the ore by means of oil of turpentine. It is only slightly soluble in alcohol and ether. When pure, it is white and crystal- line. ID'RYL. Syn. Fltjoranthene. C15O10. Ob- tained from coal-tar; it distils over above 360° C, forming a part of the crude phenanthrene. It crystallises from alcohol in needles or plates. IGNF'TION. In the laboratory, this term is commonly applied to the act of heating to redness or luminousness. See Calcination. ILLICIN. Boil a clear decoction of holly with animal charcoal; let it settle, collect the deposited charcoal, wash it with cold water, dry it, and treat it with boiling alcohol; let the filtered liquid be evaporated to dryness. Febrifuge.— Dose, 6 to 24 gr. ILLUMINA'TION. The act of illuminating or making luminous. For supplying artificial light to streets and the interiors of houses coal-gas and oils and fats are generally employed. These illuminating agents are compounds rich in carbon, upon the presence of which the brightness of their flames depends. Flame is gas or vapour heated to incandescence during the process of combustion. A flame containing no solid particles emits but a feeble light, even if its temperature is the highest possible. Pure hydrogen, for in- stance, burns with a pale, smokeless flame, though with the production of considerable heat. On the other hand, wax, paraffin, coal-gas, &c, while undergoing combustion, give out considerable light, because their flames contain innumerable solid particles of carbon, which act as radiant points. To give the greatest degree of luminosity to flame, the supply of air must be proportioned to the character of the burning substance, and be insufficient for the instantaneous combustion of the evolved gases; in which case the hydrogen takes all the oxygen, and the larger portion of the carbon is precipitated and burnt in the solid form, at some little distance within the outer surface of the flame. When the supply of air is sufficient for the immediate and complete com- bustion of the whole of the combustible matter, no such precipitation takes place, and the flame is neither white nor brilliant. The richest coal-gas, mixed with sufficient air to convert all its hydro- gen and carbon into water and carbonic acid, explodes with a pale blue flash; yet the same gas, when consumed in the ordinary way, burns with a rich white flame. Every one must have noticed the effect of a gust of wind upon the flaring gas- jets of a butcher's shop; the plentiful supply of air causes complete combustion, and so converts the bright white flames into dull blue streaks of fire. When the supply of air is insufficient to cause the combustion of the newly formed solid carbon at the instant of its development, and whilst it is in an incandescent state, the flame be- comes red and smoky, and unburnt sooty particles are thrown off. The same occurs when the tem- perature of any portion of the hydrogen is reduced below that intensity required for the combustion of the newly separated charcoal. Solid bodies, as tallow, oils, and fats, which burn with flame, are converted into the state of gas by the heat re- quired to kindle them, and it is this gaseous matter which suffers combustion, and not the substance which produces it. The relative value of the ordinary illuminating agents has been accurately determined by Dr Frankland. According to his experiments, the quantities of various substances required to give the same amount of light as would be obtained from 1 gall, of Young's paraffin oil are as follows : Young's paraffin oil . . 1*00 gall. American rock oil (acknow- ledged to be an inferior sample) .... 1*26 „ Paraffin candles. . . 186 lbs. Sperm .... 22*9 „ Wax 26-4 „ Stearic .... 27*6 „ Composite.... 29*5 „ Tallow .... 39*0 „ The following table exhibits the comparative cost of the light of 20 sperm candles, each burning 10 hours at the rate of 120 gr. per hour; also the amount of carbonic acid produced and heat evolved per hour in obtaining this quantity of light: Carb. acid Units of per hour in heat cubic feet. per hour. 8*3 6-7 10-1 3*0 82 66 100 29 Cost. s. d. Wax . .7 2^ Spermaceti . 6 Paraffin candles 3 10 Tallow . .28 Rock oil . . 0 7£ 1 Paraffin oil .06]' Coal-gas . . 0 4| . 5-0 . 47 Cannel-gas .03 . 4*0 . 32 These figures prove that coal-gas and the mineral oils are the cheapest and best illumi- nating agents, producing the largest amount of light with the least development of heat. The light emitted by incandescent lime (Drttm- MOND LIGHT, HYDRO-OXYGEN LIGHT, LIME-LIGHT, oxyhydeogen light) is intensely brilliant, and is often made use of to enable workmen to con- tinue operations at night. It is obtained by directing the flame produced by the combustion of a mixture of hydrogen (or coal-gas) and oxygen upon a small cylinder of lime. In the improved form of this light the lime is protected from crumbling by a cage of platinum wire, and is caused to rotate slowly by means of clockwork, so as constantly to expose a fresh surface to the flame. When reflected from a ' parabolic mirror' in a pencil of parallel rays, the Drummond light has been recognised during daylight at a distance of 108 miles. The lime-light produced with coal- gas and oxygen is used for the MAGIC lantern and GAS MICROSCOPE. The most powerful illuminator is the electric light, which is now being subjected to trial in many cities for street illuminations, &c, in place of coal-gas. It is usually produced by the passage of a strong current of electricity between two pencils of hard carbon. The electric light has been successfully applied to lighthouse illumina-