bottom pierced with many small holes, so as to form a strainer; and a proper quantity of boiling hot water being poured cautiously on this layer of coffee in powder, the water penetrates it by degrees, and after a certain time begins to filter through it. This gradual percolation brings continually a succession of fresh particles of pure water into contact with the ground coffee; and when the last portion of the water has passed through it, every thing capable of being dissolved by the water will be found to be so completely washed out of it, that what remains will be of no kind of value.

"It is however necessary to the complete success of this operation, that the coffee should be ground to a powder sufficiently fine.

"In order that the coffee may be perfectly good, the stratum of ground coffee, on which the boiling water is poured, must be of a certain thickness, and it must be pressed together with a certain degree of force. If it be too thin, or not sufficiently pressed together, the water will pass through it too rapidly; and if the layer of ground coffee be too thick, or if it be too much pressed together, the water will be too long in passing through it, and the taste of the coffee will be injured."

The author recommends as of importance that the surface of the coffee be rendered quite level after it is put into the strainer, before any attempt is made to press it together, that the water in percolating may act equally on every part. For this purpose he uses the following contrivance :-" The circular plate of tin, with a rod fastened to its centre, which serves as a rammer for pressing down the ground coffee, has four small projecting square bars, of about one-tenth of an inch in width, fastened to the under side of it, and extending from the circumference of the plate to within about one quarter of an inch of its centre. On turning this plate round its axis, by means of the rod which serves as a handle to it, (the rod being made to occupy the axis of the cylindrical vessel,) the projecting bars are made to level the ground coffee; and after this has been done, and not before, the coffee is pressed together.

"This circular plate is pierced by a great number of small holes, which permit the water to pass through it, and it remains in the cylindrical vessel during the whole of the time that the coffee is making. It reposes on the surface of the ground coffee, and prevents its being thrown out of its place by the water which is poured on it. The

rod which serves as a handle to this circular plate is so short, that it does not prevent the cover of the cylindrical vessel from being put down into its place."

Two-thirds of an inch answers best for the coffee in powder before it is pressed together, and the pressure should be such as to reduce the thickness to something less than half an inch.

"A Table, showing the diameters and heights of the cylindrical vessels (or strainers) to be used in making the following quantities of coffee:

As these heights are nearly equal, the Count recommends that the strainers be all made of the height of 5 inches, and suspended in their reservoir at such a height that their bottoms be above the percolated fluid when all has passed through.

"The reservoir and its boiler, he then observes, must be soldered together above, at their brims; and the reservoir must be suspended in its boiler, in such a manner that its bottom may be about a quarter of an inch above the bottom of the boiler.

"The small quantity of water which it will be necessary to put into the boiler, in order that the reservoir for the coffee may be surrounded by steam, may be introduced by means of a small opening on one side of the boiler, situated above, and near the upper part of its handle.

"The spout through which the coffee is poured out passes through the side of the boiler, and is fixed to it by soldering. The cover of the boiler serves at the same time as a cover for the reservoir, and for the cylindrical strainer; and it is made double, in order more effectually to confine the heat.

"The boiler is fixed below to a hoop, made of sheet-brass, which is pierced with many holes. This hoop, which is one inch in width, and which is firmly fixed to the boiler, serves as a foot to it when it

is set down on a table, and it supports it in such a manner that the bottom of the boiler is elevated to the height of half an inch above the table.

"When the boiler is heated over a spirit lamp, or over a small portable furnace in which charcoal is burnt, as the vapour from the fire will pass off through the holes made in the sides of the hoop, the bottom of the hoop will always remain quite clean, and the tablecloth will not be in danger of being soiled when this coffee-pot is set down on the table.

"As the hoop is in contact with the boiler, in which there will always be some water, it will be so cooled by this water as never to become hot enough to burn the table-cloth.

"The bottom of the boiler may be cleaned occasionally, on the underside, with a brush or a towel; but it should not be made bright; for when it is bright it will be more difficult to heat the water in it than when it is tarnished and of a dark-brown colour.

"But the sides of the boiler should be kept as bright as possible; for, when its external surface is kept clean and bright, the boiler will be less cooled by the surrounding cold bodies, than when its metallic splendour is impaired by neglecting to clean it*.

"As the small quantity of water which is put into the boiler serves merely for generating the steam which is necessary in order to keep the reservoir and its contents constantly boiling-hot; if the reservoir be made of silver, or even of common tin, the boiler may, without the smallest danger, be made of copper; or of copper plated with silver, which will give to the boiler an elegant appearance, and at the same time render it easy to keep it clean on the outside.

"The boiler may likewise be made of tin, and neatly japanned on

"I have in my possession two porcelain tea-pots, of the same form and dimensions, one of which is gilt all over on the outside, and might easily be mistaken for a gold tea-pot; the other is of its natural white colour, both within and without; being neither painted nor gilt. When they are both filled at the same time with boiling water, and exposed to cool in the same room, that which is gilt retains its heat half as long again as that which is not gilt. The times employed in cooling them a given number of degrees, are as three to two.

"The result of this interesting experiment (which I first made about seven years ago) affords a good and substantial reason for the preference which English ladies have always given to silver tea-pots. The details of this experiment may be seen in a paper published in the Memoirs of the French National Institute for the year 1807."

the outside, provided the hoop to which it is fixed below be made of copper; but this hoop must never be japanned nor painted; and it must always be made of sheet-copper or silver; and the boiler must always be heated over a small portable fire-place or lamp, somewhat less in diameter above, than the hoop on which the boiler is placed.

"In order that the flat bottom of the boiler may not smother and put out the fire, the brim of the small furnace or chafing-dish, which is used, must have six projecting knobs at the upper part of it, each about one quarter of an inch in height, on which the bottom of the boiler may rest.

"If these knobs (which may be the large heads of six nails) be placed at equal distances from each other, the boiler will be well supported; and as the hot vapour from the fire will pass off freely between them, the fire will burn well. As a very small fire is all that can be wanted, no inconvenience whatever will arise from the heating of the boiler on the table, in a dining-room or breakfastroom, especially if a spirit lamp be used; and the quantity of heat wanted is so very small, when the water is put boiling hot into the boiler, that the expense for spirits of wine would not, in London, amount to one penny a day, when coffee is made twice a day for four persons.

"It is a curious fact, but it is nevertheless most certain, that in some cases, spirits of wine is cheaper, when employed as fuel, even than wood. With a spirit lamp constructed on Argand's principle, but with a chimney made of thin sheet iron, which I caused to be made about seven years ago, (and which has since become very common in Paris,) I heated a sufficient quantity of cold water, to make coffee for the breakfast of two persons, and kept the coffee boiling hot, one hour after it was made, with as much spirits of wine as cost two sous, or one penny English money."

[Count Rumford.

SECTION XVI.

Cocoa.

Cocos. LINN.

THE Cocoa-tree is a native of very warm climates. The genus includes five species, which are found in the tropics, India, and South America. Of these, two are highly valuable, the cocos nucifera, or cocoa-nut tree; and the cocos butyracea, or palm-oil tree. We shall glance at each of them.

1. Cocoa-nut Tree.

Cocos nucifera.-LINN.

This tree rises to the height of sixty feet, and is slenderer in the middle than towards the top or bottom. The leaves or branches are often fourteen or fifteen feet long, and twenty-eight in number, winged, of a yellow colour, straight and tapering. The pinnæ are green, often three feet long next the trunk, but diminishing in length towards the extremity of the branches, which are fastened at top by brown filamentous threads, that grow out of them, of the size of ordinary pack-thread, and are interwoven like a web. The nuts hang at the summit of the trunk in clusters of a dozen each. The incrusted white-meat of the nut is formed of the interior fluid, which is continually concreting as it ascends from the root. The interior fluid, or milk, as it is called, is often upwards of a pint. The leaves are wrought into brooms, mats, sacks, hammocks, and other utensils. In its original production this tree was probably an Asiatic plant; but it is now found in almost all the warm parts of America. It may be propagated in our own country from the ripe nut, which should be kept in large pots of sand during the voyage; and if it should shoot in the course of the passage it will be so much time gained. But the nuts brought to England for sale will seldom answer for the purpose of propagation, as they are almost always plucked before they are ripe, that they may the more safely endure the voyage.

The inhabitants also draw from the tree itself a very agreeable liquor, which the Indians call sura, and the Europeans style palm wine; and indeed it is little inferior to Spanish white wine, except