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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    CIIARACTKKS OR MlNLKAl.S. -J7 Pitchstone, slaty (Th. 392).—Newry. Yields with difficulty to the knife; streak white. In the forceps becomes white, and fuses on the edge into a blebby colourless glass. Contains some water. With borax fuses slowly, with slight effervescence, into a colourless glass. Plasma.—Hard as quartz. Translucent on the edge. In the forceps becomes white, but is infusible. Contains a good deal of water. With borax, a small fragment dissolves slowly; with carbonate of soda effervesces briskly, and dissolves speedily. Pleonaste (Black Spinel). (Th. 213; Al. 165).—Amity, New York, North America. Scratches quartz; brittle. Infusible alone. No water. With borax fuses Avith gi-eat difficulty. Polymignite (Ph. 261).—Priedrichsvarn, Norway. Hardness = 5-5; streak pale brown. In the forceps infusible. With borax effer- vesces, and fuses rather easily into a glass coloured by iron. Prehnite ( FideEdelite). (Th. 274; Al. l io).—Hesists the knife; hard- ness about = 6'0. In the forceps whitens; the fibres diverge; it iu- tumesces and effervesces much, and fuses readily into a pale green transparent globule, slightly blebby. No trace of water. With borax effervesces much at first, and fuses readily into a transparent glass coloured by iron while warm. Does not gelatinize with nitric acid. Prehnite (Th. 274 ; Al. 110).—Scotland. Resists the knife. In the forceps it becomes white; intumesces and efferv'esces much, and fuses into a colourless blebby globule. No water. With borax it fuses, with effervescence, very quickly into a colourless glass, and dissolves in very large quantity. [In microcosmic salt, dissolves more slowly than in borax, with effeiwescence, into a colourless bead, leaving a siliceous skeleton.—En.] Psilomelane.—Glenmalure Mine, coimty Wicklow. Hardness = 6-0. Decrepitates when heated ; infusible. Psilomelane, botryoidal (Th. 508)—Siegen, on the Rhine. Hardness = 6-0 ; poAvder nearly black. Infusible ; not attracted by the mag- net after roasting. Contains a little water. Pycnite (Fide Topaz). (Th. 254; Al. 174).—Altenberg, in Saxony. Brittle; scratches quartz feebly. In the forceps it decrepitates a httle, becomes Avhite and opaque, and is infusible. Contains no water. With borax it fuses sloAvly into a colourless glass. Pyrargyllite ( Vide lolite). (Th. 238; Al. 318).—Helsingfors, in Fin- land. Hardness about = 3-25 ; yields easily to the loiife; streak white. Small fragments are translucent on the edge. In the forceps cracks a little, becomes white ; in a good blast it glazes on the edge. Heated with nitrate of cobalt, it becomes pale blue. Contains a con- siderable portion of water. With borax dissolves very sloAvly into a transparent glass, feebly coloured by iron while warm. Yery rare. Pyrites, cockscomb (Ph. 212).—Derbyshire. Yields with difficulty to the knife; hardness about=6; streak greyish-black. On charcoal it blackens; emits pungent fumes, and fuses readily into a globule, roAigh and magnetic when cold.