Bulk for bulk, the sand is
2-1/2 times as heavy.
In practice, the weight of the bottle filled with water will probably be
already known; if not, it must be determined. A certain quantity, say 20
grams, of the powdered substance is then transferred carefully to the
bottle. The bottle need not be dry inside, but its neck and outside must
be. In making this transference a careful worker will make no loss, and
the mode of working saves a little time. But it is better to weigh the
dry flask; put into it 10 to 20 grams of the powder, and weigh again.
The increase in weight gives accurately the weight of powder in the
bottle. About two-thirds fill the bottle with distilled water, and mix
with the powder by gentle shaking. Air bubbles will disentangle
themselves, and rise to the surface of the water. Wash back anything
adhering to the stopper with a jet of water, and fill the bottle almost
to overflowing. Allow it to stand for a minute or so; replace the
stopper; warm to the required temperature; take off the superfluous
moisture; wipe and weigh. As an example, take the following:--
1. Weight of bottle 12.681 grams
2. " " bottle filled with water 37.708 "
3. " " bottle with wolfram 40.821 "
4. " " bottle with wolfram and water 61.
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