its use, in the still, is the same as that of the cap over this alembic, to condense the hot vapour."

Lucy asked why the worm was used instead of the cap

"Because," said Sir Rupert, "it exposes more cold surface to the vapour. Suppose the whole pipe to be unwound and laid open, you would then perceive what a large surface there would be. Besides which, the colder the worm is kept the quicker the condensation proceeds; and a worm, or a long pipe coiled up, is very conveniently placed in a vessel of cold water, which may be changed whenever it becomes warmed by the hot vapour that communicates its heat to the metal

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worm."

"I understand it now, thank

said Lucy.

you, sir,"

She perceived, that in fact, though the apparatus was different, the thing done was no more than what she had formerly seen when she was six years old, when the

cold plate was held over the vapour of boiling water, that issued from the top of the tea urn. She recollected something of

the account of distillation and sublimation in "Conversations on Chemistry," and searching for the book in the library she refreshed her memory by reading the passages over again at this moment, when she had the advantage of seeing the real things, and perhaps of seeing the experiments tried.

She there found that sublimation is the name given to the process of distillation, when applied to solid substances.

"Sublimation-a sand-bath-flowers of sulphur," she repeated, wishing earnestly that she could see all these things.

Sir Rupert said, that as the sand-bath was now heated over his little stove, for his own experiments, he could easily gratify her curiosity. If she pleased he would, however, instead of flowers of sulphur, let her see flowers of benzoin.

He put into her hand a small lump of

a brownish substance, which he told her was benzoin: and that it was a resin, or more properly a balsam, obtained from certain trees which grow in the East Indies, chiefly in the island of Sumatra. From

this substance flowers of benzoin are obtained by sublimation, in the same manner as flowers of sulphur are produced. Lucy watched the process.

The benzoin was put into the glass alembic, which was placed in the sandbath; and this she saw was merely a castiron vessel, containing a quantity of sand. Sir Rupert explained to her, that the heat was more uniform, and could be better regulated by means of the hot sand, and that there was less danger to the glass, than if it were exposed to the direct heat of the fire. He told her also, that chemists make much use of a bath of boiling water; and that in some arts, tempering certain kinds of springs for instance, workmen use baths of melted lead, or tin, or some other fusible substance, because the exact temperature at which these metals melt

being known, the proper heat may be applied with the greatest precision.

In a short time the benzoin began to swell; the resinous parts, and other impurities with which it had been combined, remained at the bottom of the alembic, but the volatile parts flew off, and were condensed by the cold cap. These were the flowers, and were different from what Lucy expected to see. They were more like flakes of snow, than any thing else to which she could compare them. While she was looking at them, Harry ran out into the yard to the gardener's boy, whom he saw coming in from the garden, with a basket of herbs on his arm. From his basket Harry plucked a sprig of rosemary, and returning without letting Lucy see what he had in his hand, he sprinkled it over with flowers of benzoin, and then held it before her eyes.

"It looks exactly as if it were covered with hoar frost!" cried Lucy. "How beautiful! I shall never forget this, Harry. But here are the horses coming out for

Sir Rupert and papa to ride, and so there is an end of all things-at least in the laboratory, for this day."

BATTLEDORE and shuttlecock was kept up one rainy morning by Harry and Lucybelieve it who may, boast as much who can, two thousand three hundred and twenty-four times. They had also many a game of nine-pins in the great hall, where, prolonged by its echoes, was often heard the heart's light laugh, at the fall of the merry men all.

But all these the promised joys of Digby Castle, each proving greater in the enjoyment than the promise, were exceeded by the delights of the workshop and laboratory. Every morning they watched for the moment when Sir Rupert moved towards the iron door: Avicena never watched more anxiously the famous library door, that opened but once a year.

One morning Lucy observed a shallow