Put a little ether into a bottle of caoutchouc, close it tightly, soak
it in hot water, and it will become inflated to a considerable size.
These globes may be made so thin as to be transparent.
A piece of caoutchouc, the size of a walnut, has thus been extended to
a ball fifteen inches in diameter; and a few years since, a caoutchouc
balloon, thus made, escaped from Philadelphia, and was found 130 miles
from that city.