Chapter L: M. Ives, of Boston, will please pardon us (or rather our printer) for

the mistake in the Journal in his name and locality. Mr. I. being himself a sure operator, will certainly pardon a failure in others. We will endeavor to do better in future.

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N. E. Sissons, of Albany. This gentleman has completed an extensive addition to his former establishment. W e find here one of the most substantial proofs that close application and honorable dealing are awarded by success. Mr. S. has now five rooms--one for reception, a gallery or operating room, and three stock rooms. It is highly gratifying to his friends to learn of his success, and we predict for him a large and profitable business. We have ordered one of C. C. Harrison's best full sized camera tubes, and one of W. & W. H. Lewis' camera boxes, which will be forwarded to Mr. S., he being entitled to it from the fact that he has obtained for us the largest list of subscribers. He is a "practical operator."

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J. D. Wells, Northampton, Mass., has recently fitted up a large establishment in that place. Mr. W. is an old an experienced operator, and has five rooms in his establishment, a very fine sky and side light, and is prepared to execute such likenesses as will please the inhabitants of that beautiful village in the valley of the Connecticut.

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=SUBMARINE TELEGRAPH BETWEEN ENGLAND AND FRANCE.=

The project of constructing a submarine telegraph between England and France, across the Straits of Dover, first announced during the year 1349,[A] has been in part accomplished. The following description of the laying down of the wire, we copy from an English Journal:--

[Footnote A: See Annual of Scientific Discovery, 1850, page 128.]

At one o'clock the steamer Goliath was ready to start across the Channel, with all the necessary apparatus on board, and a crew of about thirty men. Between the paddle-wheels, in the centre of the vessel, was a gigantic drum, or wheel, nearly fifteen feet long and seven feet in diameter, weighing seven tons, and fixed on a strong framework. Upon it was coiled up, in careful, close convulsions, about thirty miles of telegraphic wire, one-tenth of an inch in diameter, incased in a covering of gutta-percha, the thickness of the little finger. The point proposed to be reached, Cape Grinez, the nearest landmark to the English coast, and between Calais and Boulogne, is a distance of twenty-one miles, so that a surplus supply of nine miles of wire was held in reserve for the purpose of slackening. The connecting wires were placed in readiness at the Government pier in the harbor, and likewise at the Cape, where they run up the face of the acclivity, which is 194 feet above the sea-mark.

Some interesting experiments were first made upon a small scale to show the practicability of the plan. A mile of wire was paid out off the deck, from the pier to Shakspeare's Cliff, and the sinking process was proved to be a practicable performance. A communication was also sent through twenty four miles of wire. On Wednesday morning the experiment of sinking submarinely was practically commenced. The Goliath put out to the pier, with her telegraphic tackle and apparatus on board, under a calm sea and sky and a favoring wind. The connection between the thirty miles of telegraphic wire was then made good to 300 yards of the same wire inclosed in a leaden tube on shore, to prevent it being bruised by the shingle on the beach, and to enable the experimenters, as they proceeded out to sea, to send communications on shore. The vessel steamed out at the rate of three or four miles an hour into the open sea, in a direct track for Cape Grinez. The wire weighed five tons and the cylinder two. The operation of paying out the thirty miles of wire commenced on a signal to the sailors to "Go-ahead with the wheel, and pay out the wire," which was continuously streamed out over a roller at the stern of the vessel, the men at every 16th of a mile being busily engaged in riveting on to the wire, square leaden clamps, or weights of iron, from 14 lbs. to 24 lbs. in weight, which had the effect of sinking the wire to the bottom, which, on the English coast commences at a depth of 30 feet, and goes on varying from that to 100 and 180 feet, which latter, or 30 fathoms, is the greatest depth.

The whole of the casting out and sinking was accomplished with great precision and success, owing to the favorable state of the day. The only conjectured difficulty on the route was at a point in midchannel, called the Ridge, between which and another inequality called the Varne, both well known and dreaded by navigators, there is a deep submarine valley, surrounded by shifting sands, the one being seventeen miles in length, and the other twelve, and in their vortex, not unlike the voracious one of Godwin Sands, ships encounter danger and lose their anchors, and trolling nets of fishermen are frequently lost. Over this, however, the wire was successfully submerged, below the reach, it is believed, of either ship's anchors, sea-animals, or fishing nets. The remainder of the route, though rougher on approaching the coast of France, was accomplished cleverly, but slowly. A communication, dated Cape Grinez, Coast of France, half past eight, P. M., and received at Dover by submarine telegraph, was as follows:--"The Goliath has just arrived in safety, and the complete connection of the under-water wire with that left at Dover this morning is being run up the face of the cliff; complimentary interchanges are passing between France and England, under the strait and through it, for the first time."

Notwithstanding this apparently successful result of the work, the line was cut asunder soon after the connection was completed on the rocks near Cape Grinez, the physical configuration of the French coast being very unfavorable. The precise point where the breakage took place was about two hundred yards out to sea, just where the twenty miles of electric line that had been laid down from Dover joins on to a leaden tube designed to protect it from the surge beating against the beach, and which also serves a similar purpose up the front of the cliff to the station upon the top. The leaden conductor, it would appear, was of too soft a texture to resist the oscillation of the sea, and thereby became detached from the coil of gutta-percha wire that was thought to have been safely encased in it. The occurrence was, of course, quickly detected by the sudden cessation of the series of communications, though it was at first a perplexing point to discover at what precise spot the wire was broken or at fault. This, however, was done by hauling up the line at intervals, a process which disclosed the gratifying fact, that, since its first sinking, it had remained in situ at the bottom of the sea, inconsequence of the leaden weights or clamps that were strung to it at every sixteenth of a mile. The experiment, as far as it has gone, proves the possibility of the gutta percha wire resisting the action of the salt water, of the fact of its being a perfect waterproof insulator, and that the weights on the wire are sufficient to prevent it being drifted away by the currents, and for sinking it in the sands.

The work at present has been suspended, but will be resumed again during the spring of 1851; a somewhat different plan, however, has been proposed to be followed from that at first adopted. Instead of one slender wire, it is intended to lay down cables inclosing four lines. These cables will be composed of gutta-percha, four or five inches in thickness, the whole encased in wire rope, chemically prepared, to protect it from rot, and kyanized. There will be two of these cables, each twenty miles long, and three miles apart, the whole weight representing 400 tons; and it is expected, when chained down in the bottom of the sea, they will be of sufficient consistency and strength to resist the anchor of a 120-gun ship. The expense of the cables is estimated at £40,000. It is thought that the whole work may be accomplished by May, 1851.--_Annual of Scientific Discovery._

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=ACTION OF SOLUTIONS OF CHLORIDES AND AIR ON MERCURY.=

We have given in previous Numbers the results of M. Mialhe's experiments on the action of chlorides on some mercurial compounds, and he states that he had nearly concluded his experiments when it occurred to him to try whether mercury itself would not be acted upon by this class of substances.

Experiment, he states, confirmed his suspicions, for he found that the solutions of the alkaline chlorides put into contact with mercury and atmospheric air always produced bichloride of mercury, the quantity of which was greater in proportion to the concentration of the solution of the chloride, and the more perfect state of division of the metal, but no effect is produced unless oxygen, that of the air being sufficient, is present.

_1st Experiment._--Mercury treated with the solution of alkaline chlorides (described in our last Number as the assay liquor ), gave by stove heat 0·4 part of sublimate.

_2nd Experiment._--The above repeated with the mercury finely divided by mucilage, yielded 0·7 part of sublimate.

The researches already detailed sufficiently prove, in the opinion of M. Mialhe, that the decomposing power of the alkaline chlorides is great, but they do not teach us anything as to their relative energy. The following experiments will supply this deficiency.

_Hydrochlorate of Ammonia._--One hundred and twenty parts of hydrochlorate of ammonia and 30 parts of calomel were placed in an open bottle containg 1000 parts of distilled water, the temperature of which was gradually raised to 122° Fahr., and kept for half an hour; the sublimate produced amounted to 0·9 of a part.

The experiment repeated with the following salts gave the annexed quantities of sublimate:--

Chloride of Sodium, 0·4 of a part.
Chloride of Barium, 0·4 "
Chloride of Potassium, 0·3 "

It results from these experiments that the hydrochlorate of ammonia is the most powerful of these four salts.

In concluding his experiments, M. Mialhe remarks that the reactions which he has pointed out take place at common temperatures, but better at the temperature of the human body. All of them are produced in a short time, and some occur instantaneously, the greater part requiring only a few hours' contact for action. As then the different fluids contained in the human body contain oxygen, chloride of sodium, and hydrochlorate of ammonia, accompanied or not with hydrochloric and other acids which may facilitate their action, it follows that all the chemical phenomena produced under the circumstances described, occur in the human body when any mercurial preparation whatever is introduced into it; these always produce a certain quantity of corrosive sublimate in which their medicinal properties reside; and this fact explains, in the opinion of M. Mialhe, the hitherto unexplained physiological action and therapeutic properties of metallic mercury when introduced into the animal economy.--_Ann. de Chim. et de Phys._, Juin 1842.

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=THE HEAT OF COMBINATIONS.=

Every molecular change in the condition of matter is almost invariably connected with the evolution or absorption of heat, and the quantity of heat thus set free or absorbed bears always a definite relation to the amount of the mechanical or chemical action. To ascertain this relation has been the object of my investigations, and the following are a few of my principal results. 1. The solution of a salt in water is always accompanied by an absorption of heat. 2. If equal weights of the same salt be dissolved in succession in the same liquid, the heat absorbed will be less on each new addition of salt. 3. The heat absorbed by the solution of a salt in water holding other salts dissolved is generally less than that absorbed by its solution in water. 4. The heat absorbed by the solution of a salt in the dilute mineral acids is generally greater than that absorbed by its solution in water. In reference to the combination of acids and bases, the heat developed during the union is determined by the base, and not by the acid. An equivalent of the same base combined with different acids produces nearly the same quantity of heat. When a neutral salt is converted into an acid salt by combining with one or more equivalents of acids, no disengagement of heat occurs. When a double salt is formed by the union of two neutral salts, the same is the case, but when a neutral salt is converted into a basic salt, there is a disengagement of heat. When solutions of two neutral salts are mixed, and a precipitate formed from their mutual decomposition, there is always a disengagement of heat, which, though small, is perfectly definite in amount. The diamond disengages 7,824 units of heat during its combustion in oxygen gas, in the form of graphite, 7,778 units, and in that of wood charcoal, 8,080.--Dr. Andrews before the British Association at Birmingham.

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[The following papers have been furnished us by Mr. Pirsson, one of the former editors of the Eureka, they having been previously published in that Journal; for the cuts, which will appear in our next number, we are indebted to Mr. Starr, one of the present editors of the _Farmer and Mechanic_, and formerly publisher of the _Eureka_.]

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=DAGUERREOTYPE.=

BY JOHN JOHNSON.

As a general thing, however perfect any invention may be deemed by the inventor or discoverer, it falls to the lot of most, to be the subject of improvement and advancement, and especially is this the case with those new projects in science which open an untrodden field to the view of the artizan. Such has been in an eminent degree, the case with the discovery first announced to the world by Mons. Jean Jacques Claude Daguerre, of Paris, in the year 1839, and which excited unbounded astonishment, curiosity and surprise. It may be questioned had any other than Daguerre himself discovered a like beautiful combination, whether the world would have been favored with details exhibiting so much care, patience and perseverance as the Daguerreotype on its introduction. Shortly after these details reached the United States, by Professor S. F. B. Morse, of New York, who was, at the time of the discovery, residing in Paris. By this announcement, the whole scientific corps was set in operation, many repeating the experiments, following carefully the directions pointed out by Daguerre, as being necessary to success. Among the number in the United States, was Alexander S. Wolcott (since deceased) and myself, both of this city. On the morning of the 6th day of October, 1839, I took to A. Wolcott's residence, a full description of Daguerre's discovery, he being at the time engaged in the department of Mechanical Dentistry, on some work requiring his immediate attention, the work being promised at 2 P. M., that day; having, therefore, no opportunity to read the description for himself, (a thing he was accustomed to do at all times, when investigating any subject,) I read to him the paper, and proposed to him that if he would plan a camera, (a matter he was fully acquainted with, both theoretically and practically) I would obtain the materials as specified by Daguerre. This being agreed to, I departed for the purpose, and on my return to his shop, he handed me the sketch of a camera box, without at all explaining in what manner the lens was to be mounted. This I also undertook to procure. After 2 P. M., he had more leisure, when he proceeded to complete the camera, introducing for that purpose a reflector in the back of the box, and also to affix a plate holder on the inside, with a slide to obtain the focus of the plate, prepared after the manner of Daguerre. While Mr. Wolcott was engaged with the camera, I busied myself in polishing the silver plate, or rather silver plated copper, but ere reaching the end preparatory to iodizing, I found I had nearly or quite removed the silver surface from off the plate, and that being the best piece of silver plated copper to be found, the first remedy at hand that suggested itself, was a burnisher, and a few strips were quickly burnished and polished. Meantime, the camera being finished, Mr. Wolcott, after reading for himself Daguerre's method of iodizing, prepared two plates, and placing them in the camera, guessed at the required time they should remain exposed to the action of the light; after mercurializing each in turn, and removing the iodized surface with a solution of common salt, two successful impressions were obtained, each unlike the other! Considerable surprise was excited by this result, for each plate was managed precisely like the other. On referring to Daguerre, no explanation was found for this strange result; time, however, revealed to us that one picture was positive, and the other negative. On this subject I shall have much to say during the progress of the work. Investigating the cause of this difference occupied the remainder of that day, However, another attempt was agreed upon, and the instruments, plates, &c., prepared and taken up into an attic room, in a position most favorable for light. Having duly arranged the camera, I sat for five minutes, and the result was a profile miniature, (a miniature in reality,) on a plate not quite three-eighths of an inch square. Thus, with much deliberation and study, passed the first day in Daguerreotype--little dreaming or knowing into what a labyrinth such a beginning was hastening us.

(_To be continued._)

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=GALVANIZING DAGUERREOTYPE PLATES.=

The Battery. The best way is to purchase a good Daniel's Battery. Price $2 00. To be had at any of the dealers.

For the benefit of those who cannot procure one, I would give the following directions for making one: Procure a copper cup, (sheet copper) 6 inches high, and 4 inches in diameter; also a cup of porous earthenware, (a small unglazed flower pot answers,) or a leather cup made water tight by sewing, or even a cylinder of porous wood, (say maple or ash,) 3 inches diameter, and about 6 inches high. This is to stand in the centre of the copper cup. Now, procure a solid cylinder of zinc, 6 inches high and 1 inch diameter. This is to stand in the centre of the porous cup. Fastened to the upper end of the zinc cylinder there should be a copper wire, pretty thick. It should be held by a screw, or soldered on, and previous to the fastening, both the wire and zinc should be made clean and bright, that there may be a perfect connection. A similar wire is to be fastened, in the same way, to the upper rim of the copper cup. Let these wires be about 6 inches long. To the end of the one coming from the copper fasten a plate of pure silver, about as large as a quarter plate, unless you wish to galvanize whole plates, in which case the silver plate must be larger, say, the size of a half plate. For small plates a silver dollar, enlarged to twice its size by hammering, will answer, but is not so good. To hammer it, it must be first heated, red hot, and allowed to cool slowly. This plate is to be immersed in the silver solution, described below, near the side of the solution jar. The other wire must be bent at the end like a hook, to receive the catch. This catch may be a piece of copper wire about 4 inches long, hooked at one end, and having several turns at the other end, to strengthen it. Between these turns the Daguerreotype plate, well polished, is inserted, as in a sort of jaw. The wire holding the catch should be so bent that the Daguerreotype plate will stand from one to three inches from, and face the annode, or silver plate.

Let the silver solution be well stirred, just before immersing a plate; then, blowing away the froth and scum, immediately dip the plate, and hang it on the wire. Let it remain until it takes on a deep blue color, take it out, grasp it with the plyers, rinse it freely with clean water, and dry it carefully with a spirit lamp. Buff again to a polish, galvanize to a light blue, rinse, dry, and buff again, and it is ready for the coating box.

_Silver Solution._ Dissolve in 1 quart of soft water, half a pound of _Cyanide of Potash_. In this dissolve the _Chloride of Silver_ procurable from a silver dollar. Filter, through paper, or clean sponge, and it is ready for use, excepting that it will probably have to be reduced with water. It should be reduced till it works mellow, and free from streaks. The occasional addition of a lump of cyanide will prevent a flowery deposite of oxyde of silver. Occasionally, also, add a little chloride of silver, and more cyanide. The cyanide should always be in excess. The reason why this should be occasionally added, is that the solution becomes too strong, with the silver, from the annode. The connections must be kept bright, with a file or otherwise.

The manner of charging the above battery is as follows: Nearly fill the porous cup with water, and stir in about a tea-spoonful of sulphuric acid. Two or three drops of acid added once a week is enough. The copper cup should be filled with a saturated solution of sulphate of copper, (blue vitriol,) and the solution kept saturated by suspending in it a little sack of the blue vitriol.

[Hand] The zinc cylinder, previous to use, should be amalgamated, as follows: Place it in a plate, and brighten it by rubbing it with a swab, wet with dilute sulphuric acid. Then with the same swab, rub on mercury, until the whole surface is bright.

Chloride of Silver. Dissolve a silver dollar in about a gill of a mixture of nitric acid and water, equal parts, by the aid of a gentle heat. Let it cool. Throw it into an earthen or glass vessel, containing about 1 quart of strong salt water. Let the precipitate settle. Pour away the liquid, add a large quantity of water, let the chloride of silver settle, pour away the water, and repeat this at least fifty times. The residue is pure chloride of silver.

Any glass or earthen cup, of suitable shape and dimensions, will answer for a solution dish.

It should be remembered that a strong battery, and a strong solution require the plate to be kept at a greater distance from the annode. This distance will range from one to three inches.--_Hill's Treatise._

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=ANSWERS TO CORRESPONDENTS.=

Notice.--Those persons subscribing for this Journal will please bear in mind to write in a plain hand the name, town, county, and state. By observing the above you will save us much trouble, and, at the same time, receive the Journal with more promptness.

G. K. W., Mass.--We have been unable to prepare the chemicals you ordered. Our arrangements are somewhat extensive in the department referred to.