them by some journalists. He concludes thus: "These experiments are far from confirming the general results which have been announced; and I find it difficult to believe that good mortar will ever be obtained by the imperfect calcination of pure lime-stone. It will, probably, be necessary again to have recourse to lime-stone in which some portion of clay is mixed." FRENCH FIRE. SUCH of our readers as give implicit credit to the following amusing extract, may, perhaps, set about discovering the lost fire of M. Dupré: "A person of Dauphiné, by name Dupré, having passed his life in the study of chemistry, and in making experiments in that science, invented a sort of fire, so rapid and so powerful, that it would be impossible to avoid or extinguish it; water even increased its activity. Experiments of its effects were exhibited in the presence of Louis the Fifteenth, upon the canal at Versailles, and in the arsenal at Paris, and others in some of our ports, which made even the most intrepid among the military shudder. When it was well ascertained that a man, in possession of such an art, might soon destroy a fleet or burn a town, without its being in the power of any human assistance to stop the progress of the destruction, the king strictly forbade Dupré to communicate his sécret to any one, and gave him a recompense to remain silent. The king was at that time, it must observed, much embarrassed with being engaged in an unfortunate contest; but he could not bear the idea of increasing the miseries necessarily attendant on war, he chose rather to run the risk of a continuance of his misfortunes. A glorious example, well worthy the imitation of all sovereigns who may be placed in similar circumstances. Dupré is dead; and has, it is universally believed, carried his fatal secret with him to the grave." TEST TO DISTINGUISH IRON FROM STEEL. To distinguish iron from steel by a chemical process, take nitric acid, dilute it with so much water, that it will only feebly act upon the blade of a common table knife. If a drop of the acid thus much diluted be put upon steel, and allowed to remain on it for a few minutes, and then washed off with water, it leaves a black spot. But if a drop of the same acid be put upon iron, the spot will not be black, but of a whitish grey colour. Steel is iron combined with carbon. The black stain is owing to the conversion of the carbon of the steel into charcoal, which thus becomes predominant; and iron being nearly free from carbon, produces only a grey stain. The utility of this test is not confined to finished articles manufactured of steel, but its application enables the workmen in iron and steel to ascertain also the quality and uniformity of texture of unfinished articles, IMPERFECT SIGHT. IN the Royal Society, on Feb. 19th, a paper was read by W. H. Wollaston, M.D. V. P. R.S. on the semi-decussation of the optic nerves, which contained the following curious statements : "After fatigue arising from four or five hours violent exercise, Dr. Wollaston was affected by a partial blindness, of which he first became sensible by seeing only half the face of a person near him, and next, by seeing only the termination" son," of the name "Johnson,” His blindness was to the left of the point of vision in each eye; it was not perfect darkness, but merely a dark shade, and in about 15 minutes it gradually passed doff in an oblique direction, upwards, towards the left. Some years afterwards Dr. W. again experienced this singular kind of blindness, without any obvious cause, and first became sensible of it, likewise, by seeing only the half of a person's face; but in this case the right side of both eyes was affect ed, and complete vision was suddenly restored by the joy produced on receiving information of the safe arrival of a friend from a hazardous enterprise. Dr. Wollaston has a friend who has experienced the same kind of affection for seventeen years past whenever his stomach is deranged. Another friend was attacked by pain at the left temple and at the back of the left eye, which was succeeded by this sort of blindness on the right side of each eye; he can see to write, see the paper he is writing upon, and the pen he writes with, but not the hand that guides the pen." The affection, in this case, Dr.W, fears, is a permanent one; the pain, he thinks, arose from some pressure on the brain, and the, blindness is caused by a continuance of this pressure on the left thalamus nervorum opticum. From these facts Dr. Wollaston infers, that the opinion of the anatomists, of the left eye being supplied with optic nerves from the right thalamus, and vice versa, is unfounded, and that each eye is supplied from the thalamus on its own side. A USEFUL TEST PAPER. BOIL a pound of red cabbage leaves, minced, in a pint of distilled water till all the blue colour is extracted; then strain the liquid through a cloth or sieve, evaporate the clear infusion to half its bulk, and pour it into a shallow dish. Into this concentrated solution immerse sheets of filtering paper, each of which will absorb two ounces of the fluid; and afterwards hang them up to dry. Acids change the blue colour of this test paper into red, and alkalies change it into green. LUTHER'S COMPARISON OF CHEMISTRY. THE upright art of alchimie (said Luther) liketh me very well, and indeed it is the philosophie of the antient. I like it not only for the profit's sake, which it bringeth in melting of the metals, in excocting, preparing, and extracting, also in distilling herbs, roots, and in subliming. But also I like it for the sake of the allegorie and secret signification, which is sur passing fair; namely, touching the resurrection of the dead at the last daie. For like as in a furnace the fire extracteth and separateth that which is the best out of the matter, yea, it cometh upwards, the spirit, the life, the sap, and strength, so that it possesseth the uppermost part of the still; it cleaveth thereon, and then trickleth downwards, insomuch that the fat swimmeth above, and the best thereof hovereth always uppermost; but the unclean matter, or the dregs, is left at the bottom, like a dead carcass and worthless thing. Luther's Table Talk. TAKE three pounds of common salt and one pound of black oxide of manganese, mix them carefully together, and add as much water as will make them into a paste. Put the mixture into a retort, and add to it two pounds of sulphuric acid, of water. previously diluted with four pounds arise, which is oxymuriatic gas, A gas will instantly and must be received in an airtight vessel containing four pounds of water, in which one pound of best American pearl-ash has been dissolved. The retort may after a short period be placed in boiling water, which will extricate all the gas which can be procured. The receiver may be made of wood, but should not be larger than to contain the quantity of water specified above." SINGULAR ANALOGY BE- and snow which fell was nearly unTWEEN SEALS AND FLIES. IN the Philosophical Transactions for 1816 it was demonstrated that the feet of the common Ay are provided with cups, by which the animal is able to produce a vacuum wherever it places its foot, and thus to walk in opposition to gravity. By a paper lately read at the Royal Society, and written by Sir Everard Home, it appears that the hind feet of the walrus and seal are provided with a similar means of walking in opposition to gravity. The apparatus in the fly's feet was magnified 100 times, to make it distinctly visible, but that of the feet of the walrus was reduced to one fourth of its natural size, to bring it within the compass of a quarto plate. This discovery has, in fact, elucidated the structure of the fly's foot. In it there are two points, called pickers, the use of which was not before ascertained. Now Sir Everard has shown that two toes in the foot of the walrus, answering to those in the foot of the fly, are employed to bring the web closely down on the surface traversed, so as to enable the animal to form a more perfect vacuum, and the air is re-admitted on their being lifted up. ANOTHER DELUGE COMING. WE are sure every person has remarked as peculiar, the torrents of rain which have fallen within these few years. Accurate meteorological tables, referred to in another part of our Journal, show that in 1823 the quantity of rain precedented, and that for the last three years the quantity which fell annually has been rapidly increasing. At the same time, notwithstanding such a quantity falling from the atmosphere, it continues to increase in weight, or be more and more surcharged with moisture. It is recorded in the same tables, that the mean annual barometrical pressure of 1823 was greater than for many years past. Already 1824 has begun streaming down upon us, as if it were determined not to be outdone by its watery predecessors; and we should be greatly alarmed for the result, if it had not been lately discovered that there is a huge central fire in the earth, which has only now begun to burn with increased activity. We know there are those who dreaded, when the discovery was lately made, of the great heat in mines, that we were soon all to be burnt up; but they must now see that it is another instance of that system of compensation which has been so much insisted on by M. Azais and other writers; and the fire is now only burning briskly to keep the earth habitably dry. Timid people, indeed, among whom we do not reckon ourselves, may put a different interpretation upon it, and imagine, from the present calamitous state of the elements, that something more terrible is now to befal the human race than it ever before suffered; and that the unhappy beings of this generation are destined to be both drowned and burnt. Communications (post-paid) to be addressed to the Editor, at the London: Published by JOHN KNIGHT and HENRY LACEY, 24, Paternoster Row. B. Bensley, Bolt-court, Fleet-street, London, if in case of sudden absorption,the liquor should be brought once into the retort, the whole experiment is spoiled, or you run a risk of bursting the apparatus. The object of the improvement is to remove these evils; and besides doing that, this apparatus is much more simple and convenient than the common Woolfe's apparatus. A is the retort; B the condensor for receiving the condensable products; and C, D, and E the respective receivers. The whole joinings are fitted by grinding, so that no luting is required. The retort is tubulated, and a stop-cock for drawing off the impregnated liquid is fitted to the receiver, C. C is filled with water or whatever there is to absorb the gaseous product up to the dotted line ab; and D and E are empty. When the gas comes over, it passes into, and is absorbed by the liquid in C; if the internal pressure be strong, that liquid is forced up to the dotted line in D, and beyond that into E; and if the pressure be very great, the superabundant gas can escape by removing the conical stopper f, (the form of which is shown by Fig. 3.) To the other aperture of E there is fitted a bent tube, g, with a valve opening inwards, (shown upon a larger scale by Fig. 2); and when absorption takes place, the pressure of the atmosphere forces air through this valve, and causes the liquid to descend into the receivers; but whatever be the degree of absorption, no liquor can get into the retort, if the whole quantity at first in C be so regulated as not to come up to the orifice at B. Hence the apparatus is free from danger, at the same time that the liquid is exposed to the action of the gas in the most effectual manner. ANALYSIS OF SCIENTIFIC JOURNALS. (Continued from p. 69.) QUARTERLY JOURNAL OF SCIENCE. IN Number IV.of the "CHEMIST" we gave a specimen of the unhand some manner in which the Quarterly Journal of Science reviews books; and in the present we observe a letter from Dr. W. Henry, whose work was also reviewed in that journal, claiming, as from his talents he justly may, Ato be animadverted upon with a reasonable share of courtesy and candour." In the next Number of this scientific journal we shall probably have a remonstrance from Monsieur Blainville, on the review in the present Number, of his work on 66 fossil fish." Not having seen that work ourselves, we cannot say whether the Reviewer's quotations are correct or not; but judging from the reviews of Mr. Gurney's and Dr. Henry's books, and the review of M. Blainville's being written in the same spirit and for the same purpose, that of throwing ridicule on scientific statements, we should apprehend they cannot be relied on, and that geologists would run the risk of neglecting a work which might be of importance to their science, if they were to follow implicitly the opinions of the Quarterly. A journal which is thus unsparingly severe on others, can itself expect no mercy; and we might proceed without forbearance to comment on its contents. We might remark a great paucity in valuable original papers, and compare its own barrenness with its asperity to others. We might object to its spurious devotion to the trifles of one sect of scientific men, and its unmeasured scorn of the researches of others, as if there were bigotted parties in science as well as in politics and religion, and the Quarterly Journal were the orgau of an Orange Click, headed by Sir Humphrey Davy, Dr. Wollaston, and Mr. Brande. We might implore these gentlemen not to allow any unprincipled man, by believe they have accepted the unflattering them, to make the world worthy dignity thus conferred on them, and that they lend themselves to the odious task of unmeritedly degrading others because he stands justly rebuked. We might, |