PLAIN KNOWLEDGE.

WHY is it wasteful to wet small coal? Because the moisture, in being evapo. rated, carries off with it, as latent, and therefore useless, a considerable portion of what the combustion produces. It is a very common prejudice, that the wetting of coal, by making it last longer effects a great saving; but, in truth, it restrains the combustion, and for a time makes a bad fire; it also wastes the heat.

Why does flour of sulphur thrown into a fire-place extinguish a chimney when on fire?

Because, by its combustion, it effects the decomposition of the atmospheric air, which is, consequently, annihilated.

Why is the temperature of cold springs in general pretty uniform?

Because they take their origin at some depth from the surface, and below the influence of the external atmosphere.

Why is the same spring water which appears warm in winter deemed cold in summer?

Because, though always of the same heat, it is in summer surrounded by warmer atmosphere and objects.

Why do not springs frecze, or water freeze in pipes two or three feet under ground, when it is frozen in all the smaller branches above?

Because the earth conducts heat slowly, and the severest frost penetrates but a few inches into it while the temperature of the ground a few feet below its surface is nearly the same all the world over.

Why are white wines prepared from red grapes?

Because the must is separated from the husk of the grape before it is fermented, whence the wine has little or no colour.

Why do red grapes also produce red wines?

Because the skins are allowed to remain in the must during the fermentation, when the spirit dissolves the colouring matter of the husks, and the wine is thus coloured.

Why is the distinction in the appearance, qualities, and value of tea?

Because of the difference in the times of gathering, which takes place from one to four times in each year, according to the age of the plant: those leaves which are gathered earliest in the spring, make the strongest and most valuable tea, such as pekoe, souchong, &c.; the inferior, such as congou and bohea, are of the latest gatherings; green or lyson can be made of any of the gatherings, by a different mode of drying.

Why are we in some measure indebted

to the French for our present abundant supply of coffee ?

Because all the coffee grown in the West Indies has sprung from two plants taken thither by a French botanist from the botanic garden at Paris. On the voyage the supply of water became nearly exhausted: but so anxious was the Frenchman to preserve the plants, that he deprived himself of his allowance in order to water the coffee-plants. Formerly coffee could only be got at a great expense from Mocha in Arabia.

Why are eggs preserved by rubbing them with butter?

Because the butter closes the pores in the shell, by which the communication of the embryo with the external air take place. the embryo, is not, however, thus killed. Varnish has a similar effect. Reaumur covered eggs with spirit varnish, and found them capable of producing chickens after two years, when the varnish was carefully removed.—Knowledge for the People.

THE PELICAN.

Tue pelican, called the "large white pelican, inhabits Asia, Africa, and South America. According to Edwards, the pouch or bag nuder the bill of this bird, in which it stores up its provisions, is capable of admitting the heads of two men, or of holding twenty quarts of water. In the Alps of Savoy they call this bird the goettruse, because its panch resembles the goitres or wen, to which the mountaineers are subject. In this it deposits the fish, with which, when sufficiently macerated in the pouch, itfeeds its young. In the same receptacle it also brings water when building its nest in dry and desert places, for the refreshment of its offspring. To disgorge these, the bird presses the pouch against its breast, and this natural act has no doubt given rise to the vulgar error, that the pelican opens its breast to nourish its offspring with its blood. Be this as it may, this is no part of its history, and is now universally rejected as false, by the most esteemed naturalists. from this bird meriting to be taken as a symbol of maternal tenderness, as it fre quently was amongst ignorant nations, there are few birds which show less affection for their helpless offspring. The appetite of the pelican is extremely voracious; it takes up in a single excursion as many fish as would feast half a dozen men, It swallows easily a fish of seven or eight pounds; and we are told that it also eats

Far

rats and other small animals. Pison says, that he saw a kitten swallowed alive by a pelican, which was so familiar, that it walked into the market, when the fishermen hastened to tie its bag, lest it should slily parloin some of their fish. It eats with the side of its mouth, and when a person throws it a morsel it snaps at it. The bag of the pelican is used as a tobacco pouch. It is asserted, that when these are prepared, they are more beautiful and softer than lambs skins. Some sailors make caps of them: the Siamese form musical strings of the substance; and the fishermen of the Nile use the sac attached to the jaw as a scoop for lading their boats, or for holding water, as it neither rots with moisture nor can be penetrated by it.

where he was placed for his education, he ran away three times. He first, it is said, changed his clothes with a chimneysweeper, whose occupation he followed for some time. He next associated himself: with a fisherman, and cried flounders through the streets. His third frolic was that of sailing as a cabin boy in a vessel bound to Spain; on his arrival in which country, he deserted the ship, and hired himself to a mule driver. At length he was discovered by the English consul, who sent him back to his friends. They endeavoured to reclaim him to a life suitable to his birth and expectations, and pat him under the care of a private tutor. It is probable, however, his irregular disposition was little amended: since we uext hear of his being sent to the West Indies, where he remained for some time. He passed through many other adventures, the dates of which are not easily assignable. In a letter to M. Lami of Florence, he says, "I have conversed with the nobles of Germany, and served my apprenticeship in the science of horsemanship at their country seats. I have been a labourer in the fields of Switzerland and Holland, and have occasionally metamorphosed myself into a ploughman, and postillian. I assumed at Paris, the ridicu-. ious character of a petit maitre. I was an abbé at Rome. I put on at Hamburg the Lutherian ruff, and, with a triple chin and a formal countenance, I dealt about me the Word of God,' so as to excite the envy of the clergy." It must have been during his acting a decent part in life, that he served in two successive parliaments as a member, and belonged to the literary circles in London. His expensive habits, however, again drove him from his native country, and he thenceforth was a wanderer in the world as long as he lived. In 1759 he appeared with some credit to himself as an author. His work was entitled, "Reflections on the Rise and Fall of the Ancient Republics." He subsequently published some letters to the Royal Society, containing observations he had made on some antiquities while at Turin, and Cairo. These last articles point out that abode in the Oriental countries, which was the source of his most distinguished singularities.

It appears that having abjured Protestantism for the church of Rome, he deserted the latter for Mahometanism, to which he actually seems to have been a sincere convert, and together with which he imbibed a decided preference for eastern manners. Mr. Sharp the author of some letters from Italy, mentions in 1765 having seen Mr. Montague at Venice, shortly after his arrival from the East.

one person out of a hundred thousand knows where it is; the reason being, that there is no practical use in the inquiryall that one cares to know being how far the Thames is navigable; in short, at what point it ceases to be useful to the community. But if this be the case in a highly civilized country, how wild a business must it appear to search for the source of a river through sands and deserts, and savage, barbarous nations, merely to determine from what particular spot its most remote particle of water proceeds! In an army of soldiers, we might as well inquire which is the individual whose father or grandfather was born farthest from the capital; a question which some might call exceedingly curious, but which, we all perceive, would admit of endless, and equally useless discussion, He who embarks in an useless speculation, is subject to disappointments, which no rational being can lament; and, although we have hitherto supported Bruce both in facts and feelings, yet, in truth and justice, we have now to admit that, of the above observation, this enterprising traveller himself is a most remarkable example; for, after all his trouble and perseverance, there can be no doubt, 1st, that the fountains which Bruce discovered, are not the real source of the Nile; and, 2d, that he was not the first European who visited even them.

A-glance at any common map will show, that, at about sixteen degrees, or eleven hundred miles from the Line, at the boundary of the tropical rains, the river Nile splits into two branches-the white river and the blue river. The white river continues to run very nearly north aud south; the blue river, bending towards the east, comes from Ethiopia, or, as we term it, Abyssinia. Now, a question naturally arises, which of these two rivers is the principal stream? The Ethiopians have, of course, always claimed that distinction for the blue river; and Cambyses, Alexander, Ptolemy, and almost every one down to Bruce, looked to Ethiopia for the souces of the Nile; but the vote or verdict of man cannot alter truth; and most true it is, that the white river is the main branch or artery of the Nile. Nay, much to Bruce's honour, he himself admits this; and declares, not only that the white river is by far the larger and deeper of the two, but evidently proceeds from a more remote source; since, instead of periodically rising and falling as the blue river does (which shows that it is created by the tropical rains), the waters of the white river are everlastingly flowing-which, as Bruce justly says, denotes that the river is fed by

those distant rains, which are known to be always falling in the neighbourhood of the equator. Our honest traveller adds, that, if it was not for the constant supply of the white river, the waters of the blue, or Abyssinian river (which is formed by the union of three great streams-the Mareb, the Baviba, and the Tacazze), would be absorbed in the sands of the desert of Nubia, and that the Nile would consequently never reach Egypt. The real source of the Nile, therefore, still remains unknown, or rather it hangs in the equatorial clouds, from which the rains descend.

With respect to his having been the dis coverer of the source of the blue river, or Nile, Bruce's memory must again meet with the unsatisfactory fate which this sort of inquiry deserves; for it must be admitted that he was not the first European who visited it. Peter Paez, the intelligent Jesuit, certainly visited (one hundred and fifty years before Bruce) those fountains which he describes with very tolerable exactness; and although Bruce, eager and jealous, very naturally endeavours to detect sinall inaccuracies, yet it is perfectly evident that Paez's description is that of an eye-witness. It is true, Paez says that the fountains" are about a league, or a cannon-shot, distant from Geish,' ," whereas, on measuring this distance, Bruce found it to be only a third of a mile; but, in a strange country and atmosphere, a guess at distance is almost always an error, and a Jesuit's calcula tion of the range of a cannon-shot must, in any part of the world, have been equally liable to unintentional mistake.

But though Paez saw and described the fountains of Geish before Bruce, yet it may fairly be said, that Bruce was the person who first imparted the intelligence to the European public; for Paez's description, which was written in Portu guese, was published in Latin after his death, by Athanasius Kircher, a brother Jesuit, well known for his extensive learning and voluminous writings; and, appearing in such a form, and being also smothered with a number of improbable statements, made no progress beyond the little circle or society to which it was originally addressed.

But Bruce's solid reputation can well afford, if necessary, to throw aside altogether, the bauble for which, as a young man, he so eagerly and enthusiastically contended; and the reader has only to glance his eye over the immense country which Bruce has delineated, to admit the justice of this observation,