the vessel to see if it had gained any weight; and then
weigh the oil to find out whether it had lost any weight since it was
put into the vessel." H----'s scheme was approved.

A black Wedgwood's ware salt-cellar was weighed in accurate scales; it
weighed 1196 grains; 110 grains of oil were poured into it; total
weight of the salt-cellar and oil, 1306 grs. Six months afterwards,
the salt-cellar was produced to the children, who were astonished to
see that the oil had disappeared. The lady, who had first asserted
that Wedgwood's ware would not hold oil, was inclined to believe that
the oil had oozed through the pores of the salt-cellar; but the little
spectators thought it was more probable that the oil might have been
accidentally spilled; the salt-cellar weighed as before 1196 grains.

The experiment was repeated, and this time it was resolved to lock up
the salt-cellar, that it might not again be thrown down.

(April 14th, 1796.) Into the same salt-cellar 100 grains weight of
oil was poured (total weight 1296 grains.) The salt-cellar was put on
a saucer, and covered with a glass tumbler. (June 3d, 1796.) Mr. ----
weighed the salt-cellar, and found that with the oil it weighed
precisely the same as before, 1296 grains; without the oil, 1196
grains, its original weight: therefore it was clear that the
Wedgwood's ware had neither imbibed the oil, nor let it pass through
its pores.

This little experiment has not been thus minutely told for
philosophers, but for children; however trivial the subject, it is
useful to teach children early to try experiments. Even the weighing
and calculating in this experiment, amused them, and gave some ideas
of the exactness necessary to prove any fact.

(Dec. 1st, 1795.) _S----_ (8 years old) in reading Gay's fable of "the
painter who pleased every body and nobody," was delighted to hear that
the painter put his pallet upon his thumb, because _S----_ had seen a
little pallet of his sister _A----'s_, which she used to put on her
thumb. _S----_ had been much amused by this, and he was very fond of
this sister, who had been absent for some time. Association makes
slight circumstances agreeable to children; if we do not know these
associations, we are surprised at their expressions of delight. It is
useful to trace them. (Vide Chap. on Imagination.)

_S----_ seemed puzzled when he read that the painter "dipped his
pencil, talked of _Greece_." "Why did he talk of Greece?" said _S----_