The London dispensatory, containing: I, the elements of pharmacy; II, the botanical description ... and medicinal properties, of the substances of the materia medica; III, the pharmaceutical preparations and compositions of the pharmacopoeias of the London, Edinburgh, and Dublin Colleges of Physicians / By Anthony Todd Thomson.

  • Thomson, Anthony Todd, 1778-1849.
Date:
1830
Catalogue details

Licence: Public Domain Mark

Credit: The London dispensatory, containing: I, the elements of pharmacy; II, the botanical description ... and medicinal properties, of the substances of the materia medica; III, the pharmaceutical preparations and compositions of the pharmacopoeias of the London, Edinburgh, and Dublin Colleges of Physicians / By Anthony Todd Thomson. Source: Wellcome Collection.

    36/1096 (page 16)
    for this purpose. The following table exhibits the quantity of caloric evolved by the combustion of different substances, when all the circumstances are equal, the estimate being formed from the quantity of ice melted during the burning of one ~ pound of each of the substances. Oxygen Ice melted in lbs. Substances burnt, 1 lb. —|consumed|————— ——--]—_—_!——_—_—— in Ibs. |Lavoisier.|Crawford.| Dalton. | Rumford. Hydrogen FO ae ers) 295 480 320 Carburetted hydrogen} 4 —— — 85 Olefiant gas - - -| 3°5 — — 88 Carbonic oxide - -| 0°58 — — 25 Olive oi - 7 -. -:.-|,.3°5 148 89 104 | 93:073 Rape oil - - - -| — — — — |124°097 Wax - - - - -| 3°5 133 97 104 |126°242 Tallow .- ---. - .-|. 3°5 — — 104 {111°582 Oil of Turpentine- -| — — — 60 Alcohol - - - -| — ~ _- 58 | 67°470 Sulphuric zther - -| 3° — — 62 |107°027 Naphtha - - - -} — — — — | 97°834 Phosphorus - - -| 1°5 100 = 60 Charcoal -.- -— =| 2°8 96°5| 69 4.0 Sulphur - - - -/| 1°36 — oe 20 Camphor - - - -| — — — 70 Caoutchouc.- - -| — — — 42 From this table it appears, that hydrogen gas would form the best fuel, where a high temperature is required. c. Percussion, as far as it applies to solid bodies, is another source of caloric. Smiths, for instance, are in the habit of kindling their fires by means of an iron rod, which is smartly and quickly hammered until it become red-hot; and sparks are produced by the collision of hard bodies, particularly of flint with steel. This effect appears to arise from condens- ation or forcing the integrant particles of the bodies closer together, so as to dislodge the latent caloric they contain, and give it out in the form of sensible caloric. The specific gravity of iron is increased ‘052 by being hammered ; and it becomes so hard and brittle that it cannot again be heated by percus- sion until it has been exposed for some time to a red heat in the forge. By the collision of flint and steel the oxidizement of the steel is also effected, the sparks being small incandescent pieces of oxidized iron. d.' Friction is also a source of caloric. It is a well-known bite $oscsiils is sae alia air geal s wil eee anes)