the root, and make good wholesome bread out of it. It is only the juice which is poisonous or disagreeable in taste. But the juice itself contains a kind of starch, and when the liquid parts of it are evaporated, there remains—what do you think? Why, the tapioca of which your mother makes puddings.

But why isn't tapioca poisonous? Why is Brazilian arrowroot—which is only the manioc root dried and powdered—harmless and nutritive? What becomes of the poison, and how can we be sure that none of it remains in the tapioca or the arrowroot?

Pour a spoonful of alcohol on a plate, and set it in the air or sunshine. Then look for it half an hour afterward. The plate will be dry, and not even a smell of the alcohol will remain. Liquids which evaporate easily and completely in this way are called volatile, and the acid which renders manioc root poisonous is extremely volatile. When the least heat is applied to any mixture containing it, the acid quickly and completely evaporates, and that is the way in which it disappears in the process of making tapioca, or drying the root to make arrowroot of it. There is a small quantity of bitter material in the manioc juice which is removed by washing the tapioca as soon as it is made.

SEA-WEEDS, AND HOW TO PRESERVE THEM.

BY A. W. ROBERTS.

When visiting the sea-shore for the purpose of gathering sea-weeds, or to learn something of their modest and simple lives, it will be noticed that twice in every twenty-four hours the water advances and recedes, affording an opportunity for the collector to follow the beach down to the lowest tide-mark, and thus make sure of some small portion of the beautiful marine vegetation of the wondrous ocean.

The first band or zone of sea-weeds encountered is that of the coarse olive-green sea-weeds commonly called bladder-weed or rock-weed. This alga is easily distinguished by the double series of round air-vessels with which the fronds are studded, and the coarse midrib running up the centre of each frond. On all rocky coasts several varieties of this family of sea-weeds are to be met with. When trodden on, the air-vessels explode with a sharp report; from this fact it has been christened, by young people living on the coast, the snap-weed, to whom it affords much amusement. On this coarse weed, and under its dark and damp masses, in the tide pools and on the rocks on which it grows, are to be found many varieties of our most delicate and beautiful sea-weeds.

After the olive-green zone has been passed, the bright greens, brilliant reds, and purples are reached.

Sea-weeds are rootless plants, and do not derive their support from the earth, as do other plants, but obtain their entire subsistence from the water. The small flat disk to be found on the end of the main branch is only for the purpose of adhering to the rocks, stones, or other objects on which they may be found attached.

I have figured five of the most beautiful types of sea-weeds common on our coast, but they are so learnedly and scientifically named (being without common names), as, for instance, Polysephonia urceolata, that I have depended on the simple figures to enlist the reader's interest, and have avoided the discouraging scientific names.

On many of the apple stands in the city of New York may be seen a dark purple-colored substance for sale; this is a sea-weed imported from the coast of Ireland, and is called sloake, or lava. By many it is considered as great a delicacy as pea-nuts. When mounted, it makes a very handsome specimen. The best paper for mounting the sea-weeds is ordinary drawing-paper, cut to a uniform size.

After the specimens have been thoroughly washed, the finest should be separated from the coarser ones, and placed in wide and shallow dishes filled with clean fresh water. Sheets of the drawing-paper are slipped under the specimens, which are arranged in a natural and graceful position as they float over the immersed paper. A camel's-hair brush and a coarse needle, with the assistance of the fingers, are all that are required for the arranging of the sea-weeds on the paper. When the specimen is in proper position, it is slowly and carefully lifted from the water on the drawing-paper, so as to retain the desired position of the sea-weed.

The mounted specimen should be pinned up for a few minutes to allow the water to drip off before placing it in the press. There is no need of fastening the plants to the paper, as most of the sea-weeds are supplied with a glue-like material which fastens them firmly to the paper when in the press drying.

The most simple and cheap sea-weed press that I know of consists of two large boards, as shown in Fig. 1, at AA, and on the lower board (A) are placed layers of blotting-paper with layers of clean-washed pieces of old sheeting. The sheeting and blotting-paper layers are for the purpose of quickly absorbing all moisture from the sea-weeds. As soon as the water has dripped off the mounted specimen, it is carefully laid on two or three thicknesses of blotting-paper; on the face of the sea-weed a piece of the muslin or sheeting is laid; over the sheeting more blotters are placed, and on this second layer of blotters another set of sea-weeds. In this way all the specimens are disposed of, and the top board (AA) is placed; on this a soap box is placed, which is filled with either sand or stones, by means of which the desired pressure is obtained.

For a field press, the most simple form that I know of is shown in Fig. 2, which is made out of two pieces of three-quarter inch stuff, well strengthened with a frame of black walnut, fastened with three screws in each corner. After the sea-weeds are placed in position on one of the boards, the top board is laid on, and the specimens are brought under pressure by means of a stout strap. During the stormy days of next winter, when you are confined to the house, you will find real pleasure in arranging your pretty specimens in an album.

Fig. 1

Fig. 2

[Begun in No. 92 of Harper's Young People, August 2.]

TIM AND TIP;

OR, THE ADVENTURES OF A BOY AND A DOG.

BY JAMES OTIS,

AUTHOR OF "TOBY TYLER," ETC.

Chapter II.

SAM, THE FAT BOY.

Tim stopped as quickly as if he had stepped into a pool of glue, which had suddenly hardened and held him prisoner, and peered anxiously ahead, trying to discover where the voice came