Manual of qualitative analysis / by Robert Galloway.

  • Galloway, Robert.
Date:
1861
Catalogue details

Licence: Public Domain Mark

Credit: Manual of qualitative analysis / by Robert Galloway. Source: Wellcome Collection.

    252/272 (page 234)
    perceptible. In this cone the external mantle adac may be distinguished from the internal mantle acab, by being of a more intense blue. The holder, fig. 3, serves to hold the ec re = a. NY = » —— N <> . ge Fig.3 test specimens, which must not be larger than a millet grain, and to expose them to the action of the flame. In the two tubes aa, which are lined with cloth, two glass rods 6 6, bent at right angles, move easily in any direction. On the ends of the rods are two glass tubes ¢, drawn out to solid ends; in these are fused platinum wires, about 0°145 millimetres thick, bent at their extremities to fine loops. To allow these glass tubes to be firmly fixed to the glass rods, and yet allow them at the same time of being easily and gently pushed in and out, a silken thread, provided with a knot, is drawn through the whole length of the tube; this silken thread acts as a spring, and causes the tubes to glide easily. To bring about this, an aperture is made in the sides of the tubes through which the thread is carried.