United States or Guyana ? Vote for the TOP Country of the Week !
The opening in the fore part of this opaque coat is filled by the transparent cornea, which resembles a watch crystal in shape, and is received into a groove in the front part of the sclerotic coat in the same manner that a watch-glass is received into its case. But for this arrangement light could not gain admission to the eye.
“Not by rubbing pieces of wood together, Wilcox, but by filling my watch-glass with water and using it as a burning-glass; it lit the wood in less than a minute; only it would not do, you know, unless the sun was right overhead, and I had to wait until twelve o’clock before I tried the experiment.”
Calculate the volume of silver nitrate solution required to effect complete precipitation in each case, and add slowly about 5 cc. in excess of that amount, with constant stirring. The beaker should be covered with a watch-glass, and both boiling and stirring so regulated as to preclude any possibility of loss of material.
There is little or no disability from the unilateral paralysis of the muscles of mastication; but on account of the insensitiveness of the cornea, the eye must be protected from irritation, especially during the first month or two after the operation; this may be done by fixing a large watch-glass around the edge of the orbit with adhesive plaster.
But the small part which remains of the original edge furnishes proof in two respects that this was not a watch-glass. In the first place, on taking a careful tracing of this piece of the edge, I found that its curve was part of an ellipse; but watch-glasses, nowadays, are invariably circular.
A part of this ethereal solution is poured into a watch-glass and allowed to evaporate. If the alkaloid is volatile, oily streaks appear on the glass; if not volatile, crystalline traces will be visible.
Every substance which could attack the metal of the balance pan should be weighed upon a watch-glass, and all objects must be dry and cold. A warm body gives rise to air currents which vitiate the accuracy of the weighing. After a weight has been placed upon the pan the beam should be lowered upon its knife-edges, and, if necessary, the pan-arrests depressed.
But only one kind of glass possesses these properties; namely, that which, like an ordinary watch-glass, has curved, parallel surfaces. But for what purpose could a person wear 'watch-glass' spectacles? Clearly, not to assist his vision. The only alternative is disguise. "The properties of these spectacles introduce a very curious and interesting feature into the case.
There is only one way out of the difficulty, and that not a very satisfactory one; but Mr. Weiss seems to have adopted it in lieu of a better. It is that of using watch-glass spectacles such as I have described. "Now, what do we learn from these very peculiar glasses? In the first place they confirm our opinion that Weiss was wearing a disguise.
Cover the solution with a watch-glass; allow it to stand until cool, or preferably over night. Filter the solution through a layer of asbestos. In neutral solutions the reduction of the permanganate is less complete, and, under these conditions, two gram-molecular weights of KMnO will furnish only 48 grams of oxygen.
Word Of The Day