The blowpipe vade macum : the blowpipe characters of minerals deduced from the original observations of Aquilla Smith ; alphabetically arranged and edited by Samuel Haughton and Robert H. Scott / [Aquilla Smith].

  • Aquilla Smith
Date:
1862
Catalogue details

Licence: Public Domain Mark

Credit: The blowpipe vade macum : the blowpipe characters of minerals deduced from the original observations of Aquilla Smith ; alphabetically arranged and edited by Samuel Haughton and Robert H. Scott / [Aquilla Smith]. Source: Wellcome Collection.

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    Fuller’s Earth (Th. 216 ; Al. 307).—Nutfield, Surrey. Adheres to the tongue. Yields to the nail, and receives a polish from it; immersed in water, it falls into a pulpy mass. In the forceps it becomes brown, intumesces slightly, effervesces, and fuses readily on the edges into a greenish enamel, and forms a greyish blebby bead with difficulty. Contains water. With borax dissolves rather slowly into a transpa- rent glass coloured by iron while warm. Gabronite (Th. 289').—Stavern, Norway. Translucent on the edge. Yields to the knife: hardness about = 5-5; streak white. In the forceps, when gently heated, it becomes white and opaque, and a thin fragment fuses into a white blebby globule, which becomes trans- parent, if intensely heated. Contains little water. With borax it ef- fervesces a little at first, and fuses very slowly into a colourless glass. [Gadolinite.—Sweden. In the forceps glows intensely, and turns whitish-grey, fusing on the edge Avith slight intumescence. Con- tains water. With borax dissolves readily, giving a transparent bead coloured with iron. With microcosmic salt dissolves very slowly, and gives a transparent bead.—En.] [GadoUnite.—County Donegal. In the forceps fuses readily into a black bead, with intumescence and ebullition. Contains water. With borax dissolves readily, with effervescence at first, into a bead coloured by iron when hot, colourless when cold; Avith nitre added, behaves as before, but the bead is greyish when cold. In microcosmic salt, dis- solves, leaving a siliceous skeleton; bead coloured by iron while hot, of pearl-grey colour when cold, and somewhat opaque when nitre is added.—En.] _ Garnet. Vesuvius. In the forceps it fuses, with slight effervescence, into a dark green glass. Contains no water. With borax it effer- vesces a little at first, and small fragments fuse very slowly into a colourless glass, indicating a little iron while warm. Garnet ( Vide AUochroite, Colophonite, Cinnamon Stone, Essonite).— Resists the knife; hardness nearly = 7-0. In the forceps it fuses rea- dily into a very brilliant black magnetic globule; in the inner flame it intumesces a little. No water. With borax fuses slowly into a glass deeply coloured by iron. Garnet.—Resists the knife ; hardness about = 7'5. In the forceps in a low heat becomes opaque, but regains its transparency on coohng , fuses quietly into a brilliant black globule, not magnetic. With borax fuses slowly into a glass coloured by iron. Garnet, Pyrope or Bohemian (Th. 268; Al. 200).—It is not affected by the file. In the forceps, in a Ioaa' heat, it becomes opaque, and regains its colour and transparency when cold ; in the inner flame it effervesces, and fuses on the surface into a dark green glass, and scarcely forms a bead. Contains no water. With borax it fuses very slowly into a clear glass, indicating iron while warm, but be- comes a bright chrome green when cold. [Fuses on the edge with difficulty. With borax fuses with difficulty into a bead^ coloured permanently green, indicating: the pre.sence of chrome.—En.J
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