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Distinction of Positive and Negative
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Preservation of Seeds

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CHEAP SOUP-MAKING POT. ing that to drinking soup, it can be IF the English were only half to us only of trifling advantage; such a soup-loving people as the still, as there may be economy in French, we should think the follow-its use, we shall give a short deing invention of M. Lemaire's of scription of what he calls a calefacadmirable utility. As we, however, teur. Our plate represents a verfrom having good beef, prefer eat- tical section of this apparatus ;

ABCD is an external cylindrical vessel soldered to an internal one of the same shape, which it completely surrounds; and this species of double vessel is open at the top, while the double plate, which forms the bottom, has a hole at H, establishing a communication between the inner cylinder and the open air. By means of H C, a register, this hole can be opened and shut at pleasure. The space between the two cylinders has only three openings, one at K for pouring in water; another at L for allowing the escape of the steam, by means of the tube L M, which may, however, be dispensed with, as K will also serve for the purpose; and a third with a cock at B to draw off the water. Another cylindrical vessel, I, concentric to A, but somewhat smaller in diameter, enters it. Its upper part has a rim, and three little projections corresponding to three openings in the upper part of A, so that when these do not correspond, I does not sink quite down, and when they correspond it does, and completely closes A: it reaches only part of the way to the bottom of A. Below it there is placed, about six lines from the bottom, and nearly as large as the large vessel, a hearth or dish of cast iron, pierced with holes, and having its edge turned up all round. A third cylindrical vessel, P, having a lid, enters into the second, and shuts tight upon it. AFD is a handle by which the whole may be moved, and RSTU is a wadded cloth, which serves to wrap up the whole and keep in the heat when required. On filling the space between the two concentric parts of the vessel ABCD, the vessels I and P with water, and putting a fire on the hearth, (the capacity of water for heat being very great) we obtain a large magazine of heat, which may be preserved for a considerable time by making use of the wadded cloth. To prepare soup, put the meat and water in the interior vessel, the partition between the exterior one being also filled with water; make

a fire with a small quantity of charcoal on the hearth, e g, and then put in the interior vessel, I, which must not be allowed in the first instance to go quite down to its resting place, in order that the carbonic acid gas may escape. When the water in the inner vessel begins to boil, it is to be skimmed, and vegetables and salt added, with the other necessary ingredients to make soup. The vessel I is then again covered, and allowed to fall quite down, so as to close up the outer vessel, in which it exactly fits. The upper vessel, P, will, by this time, be found to have lost a portion of water by ebullition, and this must be replaced. The register, H C, is pushed home, all access of air is cut off, the fire goes out, and the whole is to be covered with the cloth. At the end of six hours the soup or beef tea will be found ready, and the surrounding water will still remain hot. The advantages of this method are, that it extracts all the goodness of the meat without wasting any by too fierce an ebullition; it costs but little, and requires scarcely any care in the cooking. We can readily conceive, that our soup and mirth-loving neighbours must prize such an instrument highly. They may sing or dance, or play billiards or cards, while this pot au feu makes ready their dinner without any concern their part. We need not, therefore, be surprised, that some members of the French Institute should have been commissioned by that learned body to make a report on this valuable instrument. For our parts, having long observed the proceedings of that illustrious body, we..congratulate them and the world on this useful employment of their time. M. Thenard, who has had his soup made by this instrument for upwards of three weeks, declares he will taste no soup not made by M. Lemaire's calefacteur; and Mr. Thomas Gill, the very illustrious editor of the Technical Repository, smitten with the approbation of this celebrated chemist, and the approval of the

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very learned society just mentioned, has hastened to transplant the calefacteur into the pages of that work. Although he has a great objection to the exportation of British machinery, he has, apparently, a love for the importation of French soup-kettles. In fact, he has, on this point, outstripped We had long ago selected, from the Dictionnaire Technologique, the present description and plate, as a little article of useful information; though we should never have thought, in imitation of our pomploving neighbours, of calling a soup-kettle by such a fine name as a calefacteur.

us.

INFLAMMATION OF SULPHURETTED HYDROGEN GAS BY NITRIC ACID.

WHEN a few drops of fuming nitric acid are put into a flask filled with sulphuretted hydrogen gas, the hy drogen is oxidized by the nitric acid and the sulphur is disengaged in a solid form. If the flask be closed with the finger, so that the gas which becomes heated cannot escape, its temperature is raised so much as to produce combustion, with a beautiful flame, and a slight detonation which forces the finger from the mouth of the flask.

This experiment may be made without the least danger, with a flask containing four or five cubical inches of gas. Berzelius.

ANALYSIS OF SCIENTIFIC JOURNALS.

ANNALS OF PHILOSOPHY FOR SEPTEMBER.

THOSE Who have paid any attention to the matter, have long ago seen and acknowledged that the great mass of literary and sci entific men form a separate class in society-that their pursuits are never judged of but by themselves and that they possess the singular advantage of determining public opinion as to the value of their researches and discoveries. Being the pen-holders, or secretaries, of society, they make it affirm what they please. They are themselves

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their own judges. Hence it is that we never meet with a doubt expressed in writing of the superior and almost sublime nature of every sort and species of book learning. Whatever is taken up as an amusement, as a relief from weariness, by those who are both opulent and well educated, is raised to the dignity of a noble task. During the period when monasteries existed throughout Europe, in all the pride of enormous wealth and in all the wretchedness of idleness, their inmates, having neither wives nor children to provide for, neither relations nor friends to interest their hearts, being shut out from almost all participation in the business of the world, sought relief from this state of melancholy woe in a variety of literary pursuits; and much of what they had thus recourse to as a means of getting rid of their heavy hours, they being at the same time almost the only authors, and some of them the instructors of youth, came to be considered, and is still considered, as science and knowledge. To place accurately the emphasis in a line of ancient poetry, to ascertain precisely the number of its syllables, to supply the vacancies in dilapidated manuscripts, being probably the theory of Greek stops or the history of some obscure Latin author, were some of the occupations of the monks, and still continue to be taught as the highest of alt human attainments in those worthy representatives and descendants of the ancient Benedictine monasteries, the universities of Oxford and Cambridge. In our own time we see the pursuits of the opulent and idle raised by the praise of literary men to the dignity of art, and placed on an equality with the most useful branches of industry. A nobleman who collects and admires fine pictures, or builds a magnificent mansion, is a man of taste and learning; and if he collects old books or black letter prints, and arranges them in a showy library, publishing a fine catalogue of them, he is probably described as a man of

clergyman, to have that honour conferred on him, which is all we can bestow on the memory of a Watt or a Davy. We must protest, for our parts, against an indiscriminate heaping of eulogies on insignificant persons; it tends to confound all correct notions. Approbation is the only and the highest reward men can bestow on the most useful virtues; and we ought, therefore, to be cautious how we place on the same level those who write trifling papers for their own amusement, and those who add to the knowledge and power of their species. We will believe the biographer of Dr. Conybeare, that his talents were of the first-rate description; and when this praise is balanced against his leisure and what he peformed, nothing remains worthy of being admired and recorded. We cannot, therefore, give any further account of the first article in the Annals for September, than to say it is the biography of the Reverend J.J. Conybeare, M. A., M. G. S., &c. &c.

eminent attainments, and as a benefactor to the species. In the same manner, if a wealthy rector, disdaining the occupation for which he is paid, turns over the cure of souls to his serving man, for a fourth part of his own revenue, (pocketing, like an army contractor for bread, all the difference between what he receives for performing a service and what he must pay another for doing it,) and amuses himself with prying into Saxon antiquities, or in endeavouring to find out how the world was created, he is described not merely as employing his leisure in an inoffensive mode, but as benefiting mankind by his exertions. We have no kind of antipathy to such persons, but we wish them to preserve their proper place in general estimation. They have quite enough of worldly admiration, and quite enough of worldly enjoyment from their rank and their wealth, without the humbler classes of society, to whose industry and whose exertions they are indebted for their daily bread, being also called on to reverence their amusements as wisdom, or as intended to improve the condition of man. do not wonder that such persons and such pursuits should be lauded by those who look up only to this favoured class of society for wealth, but we are surprised that a scientific journal should devote its pages to the biography of one such character. The Reverend J. J. Conybeare was, it is true, an occasional contributor to the Annals of Philosophy, and his valuable accounts of The Greek Fire," and on "Newer Red Sand-stone," being, as his biographer says, not the result of labour, but a mind demanding occupation, have secured for him a niche in the immortal temple of science, to be formed by the volumes of this work. The Rev. J. J. Conybeare was, according to his biographer, a very good sort of man; but as far as his labours are known to us, we cannot see in what way he has benefited mankind, or deserves, more than any other whist-playing or book-writing

We

In truth, the only article which seems worthy of any notice, as far as utility is concerned, is the 3d, which is by Dr. Bostock, and relates to the "Applicability of Sir H. Davy's discovery to copper vessels employed for culinary purposes." It is Dr. Bostock's opinion," that though copper is preserved by tin from the action of acetic acid in the same manner as it is from that of sea water, yet we cannot make use of this principle in vessels intended for culinary purposes, in consequence of the volatile nature of the acid."

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The remaining articles, "Herschel on certain Motions produced in Fluid Conductors, when transmitting the Electric Current; "Powell on Terrestrial Light and Heat; "Berzelius on the Combinations of Acetic Acid with Peroxide of Copper;" Gay Lussac on the Chloride of Lime"-are all too long and too forbiddingly struse and technical for our pages. The Reverend Mr. Emmet, "On the Combination of Potassium and

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the atom of oxygen in this compound volume of potash lume of potassium 18-44.11= -26.11; so that, 37.5 parts of potassium occupy a volume which may be represented by 44.11; by combustion, it combines with 7.5 parts by weight of oxygen, and the volume becomes 18; consequently the space occupied by the oxygen is negative, i. e. 26.11 of space less than 0, which is absurd." He endeavours in vain to explain this absurdity of the atomic theory; and finally concludes, "there is no parallel." We have no doubt, however, that as the theory is pushed through all its conscquences, many parallels to this in absurdity will be discovered.

In a paper on Mr. Daniell's work on Hygrometry, we find the following observations, which may be useful to some of our readers, as stimulating them to turn their attention to making barometers; and to others, as warning them not to place too much faith on these, at present, ill-made instru

ments:

"Mr. Daniell's account of the manufacture of barometers and thermometers is most certainly not overcharged. Throughout the Continent, and even in England, the business is in the hands of itinerant Piedmontese; and these artists supply not only the general public with their glittering baubles, but furnish the greater part of the most reputable instrument-makers with their whole stock of meteorological wares. Such of these as choose to graduate their own scales, must confide entirely as to the

quality of their tubes and the excellence of the filling, in one who has but indirect interest in the matter, or equivocal reputation to lose; responsibility is thus shuffled from both, and rests on neither. Such, however, are the people who by unaccountable prescription supply losophers of England, with the inthe city of London, and the philostruments which Mr. Daniell so well describes.

"If common notoriety did not bear Mr. Daniell out in his assertions, the shameful disagreement of the thermometers used by Captain Parry in his last voyage would fully do so. On one occasion this amounted to no less than 13 degrees; Capt. Parry could do nothing else than give a mean, though in such a case 489 had as good a chance of being the truth as

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UNEQUAL

DISTRIBUTION

OF HEAT IN THE PRISMATIC SPECTRUM. THAT the different portions of the prismatic solar spectrum possess different heating powers, has been universally admitted by every philosopher who has examined the subject experimentally; but a great diversity of opinion has prevailed respecting the precise point where this power resides in its greatest intensity. Landriani, "one of the first who investigated this subject, placed the maximum heating power in the yellow rays, Rochon in the orange or orange yellow, and Senebier also in the yellow. Herschel, on the contrary, found the heating power of the red to be superior to that of all the other coloured rays; but that there is a certain point of the spectrum, situated immediately beyond the red and invisible, which elevates the thermometer still higher than any of the visible rays. His experiments were directly contradicted by Leslie, but were soon after, in a great measure, confirmed by Englefield. Dr. Seebeck, in a memoir read to the Royal Academy of Sciences in Berlin, which, with numerous original experiments, com

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