Page 653 - My FlipBook

Fig. 408. Fig. 409.
Fig. 408. The incrcury spoon foicfps. An instiunient for handling nicicury when exactness in
wcipliint? is desired. It will pick up any quantity the spoon will hold, or any separate globule large
enough to be seen with the naked eye.
Fig. 409. A mercurymeter for rapidly measuring a given definite quantity of mercury in putting
it up in capsules for use in filling teeth. A certain definite quantity of alloy, say fifteen grains, is
weighed and placed in a capsule. A definite amount of mercury may be measured and placed in another
capsule ready to mix with the alloy. a. A piston that fits into the hollow cap c. The piston a
has a screw thread in the barrel on which the nut b acts as a jam-nut to fix it in any position
desired. The pislnn a may be tinned by the screw backward or forward so that it will go deeper or
less deep in the cap c. When c is placed in mercury and is filled, the instrument is closed, bringing
the rings n and ]: together. Then it is removed from the mercury and given a light tap on the dish to
remove any clinging globules. The mercury in the cap is then poured into the capsule. When the
instrument is oneo adjusted for the right amount of mercury, the repetition of the measurement is as
rapid as the mercury can be dipped and poured, and is very accurate. When the right amounts of
alloy and "f mercury are put up in separate capsules for use, both convenience and accuracy is
obtained.
42a