contrary, it is plain that laws cannot reach these evils, and those who demand them only seek to be exonerated from their own want of wariness and discretion. The proper remedy for all such evils is discretion on the part of the buyers, or a discriminating patronage by the public, by which manufacturers of bad articles, and false traders, being ruined, will always be sufficiently punished. Now for the description of our plates. Fig.1, p. 209, is a section of a blast furnace for melting the ore, showing its interior. The dark stripes on the walls are flues for the escape of moisture, which would not get off from such a massive building without injuring the walls when the heat is applied. A is the opening for the introduction of the materials; B is the body of the fur nace; C the place where the bellows enter; D the place to which the iron as it melts sinks, while the cinder floats on it and defends it from the action of the blast. The greatest heat in the furnace is a little above C; T is the tymp stones which form a bridge over the cavity in which the cinder rises in a liquid state; t is a plate to give it greater strength, and v is the outlet for the metal; d is the dam stone, and e is a dam plate to give strength to d. Figs. 1 and 2, page 210, represent a section of the refining furnace. The trough, A, is made of cast metal, the bottom consisting of fire-stone or brick; it has on three sides a hollow place, through which water flows constantly from the cistern, Cpp are two pipes from a blowing-machine, which are kept cool by water from the pipe, s, which passes off by the pipes, n, t t. The pipes, pp, are to blow the fire in A. After the metal has been melted with coke, and the blast kept up for three or four hours, the metal is drawn out at an opening at o, temporarily stopped with sand. The melted mass is received into the shallow recess, 'DE. After the metal al has undergone this refining process it is introduced into the puddling furnace, Figs. 3 and 4. A is the ash pit; C the grate; D the door for the fuel; G the cavity where the metal is laid. The flame passes over it and up the chimney, F. H is the door for putting in the metal; in the bottom of this door is a square hole for putting in the rake and other tools used by the puddler in working the metal, who can at the same time see the process through this aperture. MR. PERKINS' ACCOUNT OF HIS STEAM-GUN. "OBSERVING, while experimenting with the generator, that substances, whether metallic or otherwise, when they rose from the bottom of the generator through the tube of the stop-cock, were projected with great velocity; the thought naturally struck me, that with a properly constructed gun, projectiles might be thrown with great power and economy. It also appeared to me, that it would at once settle the important question respecting velocity, as well as power of high elastic steam. No time was therefore lost in constructing a gun, and on the first experiment my most sanguine hopes were realized, as musketballs, at the rate of 240 per minute, were projected with a velocity equal to gunpowder. I dare not speculate on the consequences of this discovery, as I feel satisfied, that the power, economy, and simplicity of this agent is such, that one projectile may be found sufficient to force any breach, or sink the largest ship, though it gives me great pleasure to hear the opinion so often repeated, that this power will be to gunpowder what that has been to the arrow. "I have found that forty atmospheres' pressure is equal to gun. powder; viz. an ounce ball discharged against an iron target from a six foot barrel about one-thirtysecond part smaller than the ball, was flattened to 2 inches in diameter; and at 45 atmospheres, its blow against the target liquified the lead. An ounce ball discharged from a musket with powder, with the common field charge, at the same distance, did not show more effect. It is said, with great plausibility, that there must be some fallacy in this experiment; for as it takes from 500 to 1000 atmospheres' pressure to propel a ball with proper effect with powder, it is asked, how can it take but 40 or 50 atmospheres of steam to do the same? Having the fact before me, I think I can find the reason, which I have no doubt is the same as that, why fulminating powder, although infinitely stronger than gunpowder, will not (though it bursts the gun) throw the ball one-twentieth part so far, the power being too instantaneous for projectiles; gunpowder being less so, gives greater effect, although the mechanical pressure is much less. Steam power, acting with constant pressure on the ball until it leaves the gun, in consequence of the nondiminishing generation of it, is, I believe, the cause of the increased effect." inform me (in your next, if convenient) how an apparatus for the rapid decomposition of water is to be formed, as I understand there is a cheap and simple one, composed of a single series of different metals, sold at philosophical instrument makers, under the name of "A galvanic apparatus for the rapid decomposition of water."And also, if I have not already tried 'your patience with my tediousness, how to cut round holes in the sides of glass cylinders. Wishing you the success that a work so useful as The Chemist" merits. I remain, Your sincere admirer, PHILO CHEMICUS. SIR, A barometer tube, after being washed out with cold water, was laid in an horizontal position, and on returning, after a few minutes absence, it was found cracked in different places. The cracks went in a straight direction for about an inch, and then turned round the tube, leaving a thin strata or coat of glass, uncracked, exposed to the air, which was easily broken. Since the circumstance occurred, it has been mentioned to several persons, and it appears that similar accidents have happened to them. They are of opinion that the thicker the tube the more likely the accident is to occur; that hot steam will occasion the same thing; but · cannot account for it except by mere conjecture. You would much oblige me, sir, by inserting this in your useful and scientific publication. Perhaps some of your correspondents may be able to explain the cause of this disaster. Is it the unequal expansion of the tube, or some fault in the annealing of the glass? d I am your's, &c. EXPERIMENTUM. GRAFTING VINES. Ir has long been an opinion among gardeners and botanists, that the proper time for grafting vines was January and February, for vines growing under the glasses; and March, for those growing in the open air. But (says Mr. Braddick) out of 40 or 50 vines which I operated on in the above months, few grew, and those which did grow were weakly, and were as long before they bore fruit as if they had been seedlings planted in the place of old vines. He observed that all the plants bled profusely, and he tried to stop this by various means, but all without effect. One experiment, he says, I will mention, as it will serve to show the great power of the rising sap in the vine while its buds are breaking. On the 20th of March, in the middle of a warm day, I selected a strong seedling vine, five years old, which grew in a wellprepared soil, on a south-west wall. I took off its head horizontally with a clean out, and immediately observed the sap rising rapidly through all the pores of the wood, from the centre to the bark. I wiped away the exuded moisture, and covered the wound with a piece of bladder, which I securely fastened with cement, and a strong binding of waxed twine. The bladder, although at first drawn very close to the top of the shoot, soon began to stretch, and to rise like a ball over the wound. Thus distended, and filled with the sap of the vine, it felt as hard as a cricket ball, and seemed to all appearance as if it would burst. I caused cold water from a well to be thrown on the roots of the plant, but neither this, nor any other plan that I could devise, prevented the sap from flowing, which it continued to do with so much force as to burst the bladder in about forty-eight hours after the operation was performed, the weather continuing the whole time warm and genial. After some further experiments, it occurred to Mr. Braddick, "that the proper time for cutting off the heads, and grafting of vines, without incurring the danger of their suffering through bleeding, was when they had reach ed that period of their annual growth at which the sap ceases to flow thinly and rapidly. I accordingly cut the branches of several in that state, and grafted them with the cuttings of the preceding year. All these grew; the operation being that of whip-grafting, and no other covering was used than a binding of bass, surrounded with grafting clay. From these, and various other experiments which I have since made, I feel confident in stating, that healthy vines may be successfully grafted with young wood of the preceding year's growth, from the time that the shoots of the stocks in which the grafts are to be put have made four or five eyes, until Midsummer, with every prospect of the grafts growing, and without the least danger of the stocks suffering by bleeding. They may likewise be grafted with shoots of the same summer's growth, worked into the rind of the young wood, from the time that the young bunches of grapes become visible on the stocks, till July, out of doors, or till a month later under glass. The operation must not be performed later than the period here specified, because time is necessary for the young shoots of the grafts to become hard, and ripen before winter.(From the Transactions of the Horticultural Society.) PARACELSUS. MR. EDITOR,-IN the early history of chemistry no name is more famous than that of Paracelsus. Dr. Thompson says of him "that he was an impostor, and boasted of secrets which he did not possess; that he stole many opinions and facts from others; that his ar rogance was insupportable, and his bombast ridiculous; and his whole life a continued tissue of blunders and vice." If it were not that no memorials are so false as those which are inscribed on tombs, I should be disposed to believe Dr. Thompson's estimate of the character of Paracelsus somewhat erroneous. The following simple account of the inscription over the grave of Paracelsus is from a German author. "According to the monumental record on the church walls of Salzburg, Aurelius Theo TO GILD WITHOUT GOLD. PUT an ounce of sal ammoniac and half an ounce of mercury in a crucible; cover it and lute it well, for fear the mercury should escape. the crucible on a slow fire for about half an hour, and then increase the heat till the crucible de of oil-cakes, common clay,2 is red hot. "When this is the case, and a portion of Cayenne pepperA throw the composition into cold mixed together, and granulated by water, and when it is cold it will being first pressed through a sieve be as hard as a stone. Break and and then rolled in a cask. To de-a grind, and dissolve it in 1 gum-tect this it was only necessary to water, and wherever you lay a coat throw it into water. Real pepper d of this it it will look like gilt. To rato remains whole, while the artificial 900 2910 viisida pepper corns fall to powder. The BOYS TRICKS THE NOVEL- same test would answer for the TIES OF PHILOSOPHERS.sd above spurious pepper, as the flour and mustard-seed would immeSIT, the Editor of the Chemist, va a late Number of the diately become soft, and at length Chemist there is an account of as dissolve. novel and curious experiment performed by Professor Leslie. That it is entertaining and curious nobody would, I should be inclined to deny; but its novelty I at its novelty I very much question, as I rememnated, on one arm, theo surgeonol ber performing the same experie should vaccinate the other armst ment (in a different manner) when with matter taken from the first, not more than three years old. The If the first vaccination has beend way I did, and no doubt many perfect the pustules on both armsst more have done, though not soos will grow to a head at precisely w scientific, was much more simple, as not take place the system has not b the same time; and if this idoesit the apparatus consisted of nothing more than a piece of glass or to vaccination ought to be repeated.00 been properly affected, bandwithe t bacco-pipe and a pea with a pin This simple and easy test, firstlo throu, it; the latter was put in the orifice of the tube, and by brought into notice by Dr. Bryce, blowing through it with the mouth of Edinburgh, auglit never to be w the same effect is produced as by neglected.omine x int gim Professor Leslie's way, for the pear continues to dance up and down and twirl round while you continue to blow Vews awold Jud bemalt, od insbI remain, 19 16 sot Yours, obediently, boo W 10-JAMES LEWIS, Union-street, Borough, 1979 bis May 27. INFLAMING GUNPOWDER inner extremities of which just BY ELECTRICITY.p To the Editor of the Chemist. SIR,-In page 68, Art. X. of the Analysis of the Annals of Philosophy, is an account of some experiments by Mr. Woodward on the firing of loose gunpowder, which I beg leave to notice is far from being original, the same experiments having been performed by MLewthwaite, of Princes-street, Rotherhithe, an he published in count of which Journals of the Royal Institution about two years back. The firing of gunpowder was published about 206 20 years ago, in a book entitled 'Imison's Elements,' from which the following is a copy :→→→ 1 touch the water, viz. the short wire, F, and the long wire, C, which makes the communication between the water of the tube and the knob of the jar. On making the discharge, which must pass through the small quantity of water in B, and down to the table, F, in the form of a dense stream, which generally fires the gunpowder. Now you perceive, Mr. Editor, that neither of these gentlemen have yet made any discovery in firing gunpowder, which plainly appears to have been done, near 20 years ago,quxe kronis THẬN 6147 4 Yours, truly, a 0 an FOR 20A YOUNG PHILOSOPHER. bloode 1 biancar Ifother gunpowder be placed We beg leave to observe to our loosely upon any stand, and the in- Correspondent, that Mr. Woodterruption of the wire circuit be ward's experiment is not curious made indit,non making the dis- from firing gunpowder by means of charge of the jar, the spark which the electrical spark, but as showtakes place at the interruptioning the effect of different conducwill scatter the gunpowder without tors. With good conductors the firing bita But the loose gunpowgunpowder was blown away, which de may be fired if the shock be is the curious part of the experi transmitted through less perfect ment, for the inflaming power of conductors; in which case the dis- electricity is known to be sufficient charge being less sudden, or rather to melt iron; but in this instance, i proceeding in a stream, the powder the rapidity or mechanical force will be fired. The best method of with which the stream of electricity performing this experiment is that was transmitted by good conduc of Cavallo, which is as follows:- tors, was sufficient to prevent its 4 F represents gunpowder chemical power from operating, placed upon table upon and the gunpowder was not inwhich the jar, A, B is flamed, but blown away. The exa glass tube, about one foot long tract of our Correspondent, at the and a quarter of an inch uated; B ter full of water damer same time, shows satisfactorily, corks and sat its extremities. Into these ward's experiment was not new. having two that even this part of Mr. Woodtwo corks two wires are thrust, the -ED. 13 |