296

Dr. Boswell Reid describes one somewhat resembling this, but instead of having the swivel movement, it was necessary to lift the whole apparatus and to invert it. It was in reality two aspirators; one emptied itself into the other.

Dr. JOULE described the process he employed to harden steel wires for magnetic needles. The wire was held stretched between the ends of two iron rods bent into a semicircular shape. The free ends of the iron rods could be placed in connexion with a voltaic battery by means of mercury cups. Underneath the steel wire a trough of mercury was placed. When the ends of the iron rods dip into the cups the current passes through the wire, heating it to any required extent. When these ends are lifted the current is cut off, while at the same instant the heated wire is immersed in the trough of mercury.

ACADEMY OF SCIENCES.
December 5.

M. DAMOUR communicated a memoir "On Callaïs," a new hydrated phosphate of alumina, some personal ornaments made of which had been discovered in a Celtic tomb in Morbihan. The stone is a species of turquoise of an applegreen colour, which appears to be given by iron, and not by copper. The mineral is translucid, has a compact fracture like wax, is easily scratched with a file, forms a white powder, and has the density 2:50 or 2:52. It disengages water when heated to dull redness, decrepitates, loses its green colour and becomes brown, and is then very friable. It is infusible with the blow-pipe, but borax and microcosmic salt dissolve it easily without colouration. The author analysed the stone, and found the composition answer to the formula,

Al2 P+5H.

He considers that this stone answers the description given by Pliny of a stone, then called Callaïs, which modern mineralogists consider the Oriental turquoise, hence named Callaite. No sources of these minerals exist in France, and the author considers them both of Eastern origin.

M. Caron sent another memoir on the "Cementation of Iron by Carbonic Oxide and by Contact with Carbon," and this time quotes Dr. Percy's experiments in support of his assertion that carbonic oxide will not cement iron. He still insists that cyanogen is the active agent in the conversion of iron into steel, and quotes experiments to show that carbon destitute of alkalies has no effect on iron in contact with it. But when an alkali is supplied, and atmospheric air admitted, cementation is facilitated. Iron also heated with this inactive carbon in an atmosphere of ammonia is quickly cemented.

M. Blondeau presented a note "On the Action of Nitric Acid on Cellulose." In contact with concentrated nitric acid, cellulose, says the author, becomes more and more charged with that acid, until it arrives at a product having the composition C12H10O102 (NO). The product placed in dilute acid undergoes a new modification and becomes soluble in nitric acid, disengaging binoxide of nitrogen. By this decomposition it forms oxalhydric acid C12H10016 This acid still left in nitric acid further decomposes. Binoxide of nitrogen is again evolved, and oxalic acid remains. These decompositions, he says, illustrate the tendency of all-organic matter to assume a simpler and more stable form.

M. Boutin communicated a note "On the Industrial Advantages to be Gained by Cultivating the Mahonia Ilicifolia." This is the small evergreen shrub known in England as the Barberry. The author suggest that the juice of the berries of this plant may be used to furnish alcohol, of which it will yield 8 per cent., of an agreeable flavour, and suitable for making liqueurs. The wine made from it is acid and disagreeable. Further than this, he adds

CHEMICAL NEWS, Dec. 17, 1864.

that the pips when roasted made a drink very like coffee in taste and appearance, and quite as useful.

NOTICES OF BOOKS.

"Our Inheritance in the Great Pyramid." By Professor C. PIAZZI SMYTH, Astronomer Royal for Scotland. Alexander Strahan and Co., London. 1864. Pp. 400. THIS book will be read with interest by the general public, but for the scientific reader it possesses unusual charms, on account of the depth of its information, the mathematical ingenuity displayed in its leading arguments, and the interesting historical references to problems in the way of standard weights and measures, and to the discussion of metrical systems which have lately been puzzling the House of Commons, the British Association, and other learned bodies. The frontispiece is a reduction from the excellent original photograph of Mr. Francis Bedford, representing a good view of the Great Pyramid of Jizeh, and there is a coloured map of the ancient pyramid-field in Egypt, besides several well-executed diagrams illustrating points of construction. The work is dedicated to the late John Taylor, Esq., of London, who appears to have devoted his life to the study of everything relating to the Great Pyramid, and upon whose previous literary inquiries in the form of the book entitled "The Great Pyramid: why was it built?" the argument of Professor Smyth is mainly founded.

The work before us sets out with the discovery of a remarkable geometrical proportion, viz., that the height of the pyramid (486 feet) is to twice the length of the base (1528 feet) as I 3144, or very nearly in the ratio of the diameter of a circle to its circumference. Professor Smyth has reason to doubt the accuracy of the measurements stated above, and he has corrected them to

Vertical height of pyramid 486.2567 feet Breadth of base 763.8100 When, by the adoption of these numbers, the ratio comes out exactly

the latter figures suggesting the number of days in a year. If, then, the base, multiplied by two, be divided into 366 equal parts, we arrive at the "primal metron," or a length of about fifty inches, which Professor Smyth considers to have been the (larger) unit of measurement employed in the construction of the Great Pyramid, and which is exactly equal to 10.000.000th of the earth's axis of rotation!

There are other wonders wrapped up in the history of the Great Pyramid; for example, its square base is very truly oriented, or placed with its sides facing north, south, east, and west; the entrance is a narrow inclined passage opening from the north side, and above it is an air channel for the sake of ventilating the internal chambers. Both these straight channels have directions which suggest the probability of their having been employed for astronomical observation, since they point respectively to the upper and lower culminations of the Polar star of about 4300 years ago, or B.C. 2500.

The object of construction has been diligently sought for, and whilst evidence proves conclusively that all the other inferior pyramids in the neighbourhood were devoted to interment the corresponding features in this monster edifice are wanting. There is no doubt that this was the first of its kind, and that a variety of extraordinary precautions were taken to ensure the safety of its contents, and the very perfection of every part of the building. The rugged exterior is proved to be the result of the removal of the exquisitely finished marble casing stones, the last two of

NEWS

which have been demolished since their discovery, in 1837, by Colonel Howard Vyse, and the apex of the pyramid has been gradually knocked away until now there is a platform on the top "large enough for eleven camels to lie down." However, regarding the interior, there is no likelihood of its having been a royal mausoleum, as were the other pyramids; the sarcophagus is wanting, but, curious to relate, there appears in its place an elaborately finished porphyry coffer, which has been a puzzle to scientific men before and since the days of Sir Isaac Newton. From the perpendicular sides, exactly regular form, and finished workmanship of this mysterious coffer, and absence likewise of any hieroglyphic inscriptions, it has been argued that it must tell its own tale, and that the determination of its precise dimensions must be a matter of vital importance. At page 103 of Professor Smyth's book the recorded measurements of some twenty-five observers are tabulated, and it is truly lamentable to notice the wide discrepancies between their several results. It will scarcely be credited, for instance, that the French academicians committed an error amounting to nearly three inches in taking the depth both inside and outside! And will it be believed that the great master of calculations, the profound Sir Isaac Newton, met in the porphyry coffer a stumbling-block indeed? for we find him actually "taking two measures of the interior and one of the exterior," in order to get at its cubical contents! The best measurement was that taken as far back as the year 1638 by John Greaves, Savilian Professor of Astronomy in Oxford, corrected subsequently by M. Jomard, which makes the interior of the coffer to be 77.806 × 26.599 × 34 29870,982.4 English cubic inches. What is this measure? Why, exactly the cubical contents of four British quarters of wheat, or 70,982 144 English cubic inches-a lost measure rediscovered, says Mr. Smyth, for many have asked, “What do four quarters really make?" The chapter on "British Metrology " is a carefully written account embodying the history of England's standard weights and measures-a narrative full of interest. Many of our readers may remember the pint being increased in value by Act of Parliament under George IV., and the old proverbial rhyme

And old troy weight, according to which "thirty-two grains make one pennyweight," &c. And, many will remember the circumstance of the standard yard and pound being lost in the great fire which consumed the Houses of Parliament in October, 1834. How, that in the year following Francis Baily was entrusted with the reconstruction of the standards, and that he reported of the Exchequer standard yard, "that it was impossible to speak of it too much in derision and contempt; for it had been broken asunder, and the two pieces were dovetailed together; but so badly, that the joint was nearly as loose as a pair of tongs." The present standard yard is considered by Professor Smyth to be short of its true length by about one-thousandth part, and he would prefer to rely upon the Exchequer ell, which, according to Graham in 1743, was "found to be 0494 inch longer than 45 such inches as were contained in the Exchequer yard of 36 inches, but was in excess by 0075 inch of the Royal Society's scale." Therefore, 0494-0075'0419 actual excess; and 45'0419 modern inches are consequently equal to 45 old standard inches, or differ in the ratio of 1.00093: 1. If, now, the "primal metron already alluded to as having been deduced from the measurements of the Great Pyramid be divided into fifty equal parts, we obtain the smaller unit, or "pyramid inch," which is equivalent to 100069 of our present linear inches, and must be, as already shown, 500,580,000th part of the earth's

polar axis. In his table of linear measures, page 218, Professor Smyth retains the inch and foot, and proposes a new one of 25 inches to be called the "arm." This length (a half metron) the author imagines to have been employed by the Egyptian artificers as a common rule of convenient length. And it is one which has lately become a favourite scale with the British Government; thus, the new Ordnance Survey maps are said to be, but not truly, 25 inches to the mile, or one square inch to an acre. Professor Smith says:-"It is truly of the proportion of both of nature; and that gives, on the British measure, 25 344 inches to one mile, and 1018 inches to an acre as the scale of the maps."*

In reviewing the French metrical system (the introduction of which has of late been strongly advocated), Professor Smyth conceived it to be founded upon a false and uncertain basis. The usual definition of a metre is that it shall be equal in length to 10,000,000th of a quadrant of the earth's surface!" Now it has lately been shown by M. de Schubert "that the earth's equator is not a true circle, but a rather irregular curvilinear triangle, so that it has many different equatorial axes, and therefore also different lengths of quadrants in different longitudes." Admitting the advantages of a decimal system, but rejecting the French code for the reason just now assigned, our author insists upon the importance of taking a small measurement as the unit, and quotes the evidence of Sir William Armstrong and Mr. Whitworth as supporting his opinion in favour of a standard inch. Sir William Armstrong said at the Newcastle meeting of the British Association that "in the Elswick works, as well as in some other large establishments of the same description, the inch is adopted as the unit, and all fractional parts are expressed in decimals." And Mr. Whitworth in his examination before the Lords' Committee in 1855, exhibited an inch measure, with an apparatus for testing its length to the millionth of an inch; and insisted on "the greater importance to all who are engaged in the mechanical arts to have a standard foot and a standard inch, than to have a standard yard."

After giving a full description, in several chapters, of the points of construction and remarkable coincidences involved in the Great Pyramid, Professor Smyth (at p. 302) commences a most interesting account of the difficulties experienced by Francis Baily, Troughton, Kater, the Rev. R. Sheepshanks, and others, in their attempts to construct the modern standards; these failures have arisen from the alterable nature of the materials employed, and the objection is fairly met by the author in his proposal to select porphyry, or other hard, fused, and durable rock for the manufacture of these scales. The first standard of F. Baily was of drawn brass tube, and was condemned in the short space of fifteen years as having altered its size, itself from the strains of the hammering or rolling, he From wrought metal, which is always seeking to recover went to cast metal; and from a soft, flexible metal like brass, he went to hard gun-metal, with an improved result, but still far from perfection. On his death the subject was taken up by the Rev. R. Sheepshanks, who preferred pure metals rather than alloys, and had a great idea of cast copper, notwithstanding its softness, and the trouble of preparing it in a sound state. The opinion of Professor Faraday was asked, and he reported, in 1847, as follows:

"I do not see any reason why a pure metal should be particularly free from internal change of its particles, and on the whole should rather incline to the hard alloy than to soft copper, and yet I hardly know why. I suppose the labour would be too great to lay down the standard on different metals and substances; and yet the comparison

It would appear that Professor Smyth is, like the great Sir Isaac Newton, not infallible. The numbers just given are quoted literally from page 221 of the work before us, but the learned professor has surely magnified the error of the Ordnance Survey maps tenfold! A nought is required to be inserted next after the decimal point in the second instance, and their true scale becomes 10018 inches to

an acre.

298

of them might be very important hereafter, for twenty years seem to do or tell a great deal in relation to standard measures."

And later, in 1857, we find Professor Airy communicating to the Royal Society the particulars of 47 bars of gunmetal, 9 of brass, 2 of copper, 9 of forged iron, 4 of cast iron, and 6 of cast steel, then being converted into standards of British length-measure; and these constitute the sum of what the nation has to trust to through future time, the older reference to natural standards having been officially thrown overboard. Vide" Report of Treasury Commission on Standards," March 28, 1854:-"We adhere to the recommendation (offered in 1841) that no reference be made to natural elements for the values represented by

the standards."

Professor Smyth tells well the story of how the standard pound weight of platinum, prepared only ten years ago, was recently discovered to have become "coated with an extraneous substance produced by the decomposition of the lining of the case in which it was preserved." But for these and many other interesting particulars we must refer to the original work.

On the subject of heat and its registration, Professor Smyth has some good ideas. He recommends a division of the thermometer scale into 250 degrees, ranging from the freezing to the boiling-point of water, and starting (like the centigrade scale) with its zero at the freezing-point. Such small degrees would surely be very convenient, as avoiding fractions for all practical purposes, and would carry out still further the idea which has no doubt served to confirm the use of the unmeaning Fahrenheit scale in this country. The upper limit of Mr. Smyth's scale would be 10c0° (=752° Fahr.), or the point at which "iron becomes bright red in the dark," according to the "Natural Philosophy of the Society for the Diffusion of Useful Knowledge.

The same Temperature According to Five Different
Thermometric Scales.

Modified Fahrenheit.

Space will not permit of a more lengthened examination of the contents of this entertaining book. If the statements contained therein are not actual facts, then, indeed, must they be considered as a most remarkable collection of coincidences. We understand that Professor Smyth is about to proceed to Egypt to test for himself the truth of the conclusions drawn by himself and others, and he will be prepared, through the agency of magnesium and photography, to lay open to public observation the mysterious interior of the Great Pyramid. And we may hope eventually to hear from the hero of Teneriffe the relation of his successful travels, and see for ourselves the hidden recesses of one of the wonders of the world by taking no more trouble than is usually attendant upon a journey to Albemarle-street.

NOTICES OF PATENTS.

Communicated by Mr. VAUGHAN, PATENT AGENT, 54, Chancery Lane, W.C.

Grants of Provisional Protection for Six Months. 2484. James George Bechton, Whitby, Yorkshire, "Improvements in heating retort and other ovens for the distillation of shale, coal, and other substances."--Petition recorded September 20, 1864.

2884. Michael Henry, Fleet Street, London, "Improvements in the mode of, and apparatus for, carbonising wood and performing other operations in which substances are

CHEMICAL NEWS, Dec. 17, 1864.

treated by flame or heat."-A communication from Pierre Hugon, Boulevart Saint Martin, Paris, France. 2889. Septimus Piesse, New Bond Street, Middlesex, "Improvements in apparatus for creating and projecting cold vapours."-Petitions recorded November 18, 1864. 2906. Alfred Vincent Newton, Chancery Lane, Middlesex, "An improvement in the manufacture of sugar, and in the machinery to be used therein."-A communication from Charles Rostaud, Rue St. Sebastien, Paris, France. Invention Protected by Deposit of Complete Specification.

3042. George Tomlinson Bousfield, Loughborough facture of Illuminating gas.' Park, Brixton, Surrey, "Improvements in the manuWilliam Elmer, New York, U.S.A.-Petition recorded A communication from December 6, 1864.

Notices to Proceed.

1875. Jean Pierre Chambeyron, Rue de la Fidélité, Paris, France, "Certain improvements in preventing oxidation of iron or steel." 1876. Jean Pierre Chambeyron, Rue de la Fidélité, Paris, France, "Certain improvements in the manufacture of steel."-Petitions recorded July 27, 1864.

1880. Elizabeth Brinson, Frome, Somersetshire, "Improvements in envelopes or covers for bottles and jars."— Petition recorded July 28, 1864.

1931. Charles Garton, Bristol, Somersetshire, aud Thomas Hill, Southampton, "Improvements in mashing apparatus."-Petition recorded August 3, 1864.

1941. Francis Cruickshank, Edinburgh, N.B., "Improvements in coatings for the prevention of the fouling of the bottoms of iron and other ships."-Petition recorded August 4, 1864.

1963. Neil McHaffie, Broad Street, Mile End, Glasgow. "Improvements in treating iron plates for ship-building, boiler-making, and similar uses, and also wrought iron in other forms to render it capable of resisting oxidation or destruction by sea and other water, and atmospheric and other corroding influences.”—Petition recorded August 6, 1864.

2806. George Smith, Bradford, Lancashire, "Certain improvements in machinery or apparatus for drying or dessicating materials or substances containing moisture." -Petition recorded November 11, 1864.

2927. Francois Pfauhauser, Winsley Street, Middlesex, "An improved process of tanning."-Petition recorded November 23, 1864.

CORRESPONDENCE.

Continental Science.

PARIS, December 13.

A FEW weeks ago I mentioned the subject of vaccination, and called attention to the practice followed at Naples of vaccinating directly from the cow. The subject has been seriously taken up here, and it is estimated that a good commercial speculation may be made of it. A cow, it is said, will produce 100 pustules, which, at 5 francs each, will bring 500 francs, the cow suffering no deterioration in value. The practice is greatly recommended by the safety it ensures that no other contagion will be communicated along with the cowpox. Smallpox is rather prevalent in and around Paris, and people are becoming anxious on the subject. It is recommended here that the cow should be vaccinated by twelve or fifteen small punctures around the vulva, a part the animal cannot get at. The pustules ripen about the 8th or 12th day. The lymph is too thick to be got into tubes, but must be taken on glass plates, which can be moistened when the matter is wanted. A good idea has been started by one doctor, namely, that it will do just as well to drink the milk of an infected cow as to get vaccinated. The doctor has made the experiment. He vaccinated a cow on the udder

and got two good pustules. He then gave the milk to two infants, and afterwards tried to vaccinate them, but without success, while a third infant who had had none of the milk was at once inoculated by the same virus. He recommends that young ladies who are afraid of a prick with a lancet should drink a glass of milk every three or four years to save them from the small-pox!!

M. Schmidt recently communicated to the Belgian Academy some observations he made at Athens on shooting stars. He has established some numerical relations between the number of meteors, the detonations, the falls, the tails, and the colours, which may have some interest for your readers. He says that the detonations and falls are fewest when the meteors are most numerous-i.e., in August and November. The greatest number of stars fall in May. Most tails are observed when the meteors are numerous. Red and green coloured meteors are most often seen in summer. The author has noted the colour of 5671 meteors; 4300 of which were white, 905 yellow, 320 red, and 146 green.

Some more information about the Giessen Congress has now reached me through the pages of the Moniteur Scientifique, but still intrinsically very little. Most of the chemical papers read-88 per cent. of the total number, in fact-were on organic chemistry, in which department the reporter is not strong; so he shirks the matter, and, indeed, to some extent, pooh-poohs modern organic chemistry. I feel disposed to quote a portion of his remarks, for I believe that there are many chemists who would agree with the substance of them. At one of the sittings, Dr. Hofmann gave a resumé of his investigations on the chemical nature of the aniline dyes, and mentioned the interesting fact that it was five-and-twenty years ago, when a simple student at Giessen, that he began his researches on aniline, with little idea, I dare say, that they would ever receive the extensions he detailed that day.

Some other small matters deserve notice. Boettger described a method of writing on zinc, which may be useful to some of your readers, though I am not certain that the method is new in England. He takes one part of chloride of platinum and one part gum arabic, and dissolves them in ten parts of water. With the solution he writes on the zinc, and so obtains black characters, which are unaffected by dilute acids. When the zinc plate is placed in dilute nitric acid, the parts not written upon are eaten away, and the writing stands out in relief. The author suggested that this was a good way of making garden labels for plants. The same gentleman exhibited some mirrors silvered by Bothe's process. The inventor makes use of a mixed solution of ammoniacal nitrate of silver with oxytartrate of silver-(proportions not given) and the results are said to be very beautiful. Dr. De Vry exhibited a specimen of what he called "the sugar of the future." This is procured from the juice of certain palms growing in Ceylon and Java, and is, it seems, producible with great ease in large quantities. Dr. Frank described the salt deposits at Stassfurt, where, you will remember, a bed of chloride of potassium, or, rather, a layer containing a large proportion of chloride of potassium, is found to overlie a deposit of chloride of sodium. The potassium salt is separated by successive crystallisations, and is obtained tolerably pure, as the English makers of saltpetre know.

Spontaneous generation was, of course, largely discussed at the Congress, and the antiquity of man and the Neanderthal skull were subjects frequently alluded to. The possessor of that skull when alive could have little idea of the noise he would one day make in the world. Lastly, I may shortly mention the paper by Helmholtz on the sounds of muscles, which will no doubt excite great attention, since it serves to explain the first sound of the heart. The author showed that the contractions of muscles are attended with the production of sound, by which he is enabled to determine the number of vibrations

in the muscle. You will, no doubt, have the entire paper in England soon, and will see the importance of the matter to the physiologist and physician.

MISCELLANEOUS.

Renard v. Levinstein. This important trial commenced on Tuesday last, before Vice-Chancellor Page Wood. The subject in dispute, our readers will remember, is a patent for the production of a blue dye granted to M. C. A. Girard. The specification of this patent will be found below. It will be in the recollection of our readers that an injunction was granted by the Vice-Chancellor to restrain the defendant from making a blue aniline dye, which injunction was dissolved by the Lords' Justices, on the grounds that no infringement of Girard's patent had been proved, and that the validity of the patent was open to dispute. The present is a trial without a jury to establish the validity of the patent, and prove the infringement by the defendants. An unusual amount of interest has been given to this trial by the circumstance that a number of eminent French chemists have been examined for the plaintiff. Besides the patentees, MM. Girard and Delaire, of the French mint, MM. Persoz, Cahours, and E. Kopp, have given evidence, the last in excellent English. Besides these, Drs. Hofmann and Frankland, Mr. Abel, and several other London chemists, were examined for the plaintiff, whose case had not concluded at the early date on which we are compelled to go to press. In our next we shall give a succinct resumé of the evidence on both sides. In the meantime we publish the specification of the patent which is the subject of dispute. "Letters Patent to Charles Adam Girard, of 17, Boulevard du Temple, Paris, in the Empire of France, for the invention of Improvements in preparing colouring matters for dyeing and printing.'-Partly a communication from abroad by Mr. Georges de Laire, of the Mint, in Paris.

"Sealed the 9th July, 1861, and dated the 12th January, 1861. "Provisional specification left by the said Charles Adam Girard at the office of the Commissioners of Patents, with his petition, on the 12th January, 1861.

46

I, Charles Adam Girard, of 17, Boulevard du Temple, Paris, in the Empire of France, do hereby declare the nature of the invention for Improvements in preparing colouring matters for dyeing and printing' to be as follows:

"For these purposes red aniline dye is purified and mixed with a quantity of aniline. The proportions which I prefer to employ are about equal quantities of aniline and of red aniline dye. The mixture is maintained for several hours at a temperature between 155° and 180° (Centigrade), and as nearly as possible to 165°. The substance, which is now violet, is boiled with a mixture of water and hydrochloric acid. The excess of aniline and of red dye which has not been transformed is dissolved, and a violet residue remains. This residue is completely soluble in alcohols, acetic acid, wood spirit, and boiling water slightly acidulated with acetic acid. All these solutions may be employed directly for dyeing violet. In order to obtain the blue dye the violet mass is boiled several times with hydrochloric acid diluted with a small quantity of water and then washed with boiling water. The substance thus obtained is a blue having a beautiful coppery lustre. To employ this colour in dyeing it is sufficient to dissolve it in vinegar, or alcohol, or wood spirit, and to dilute these solutions with a convenient quantity of water. I would state that liquids obtained by treating the violet mass with hydrochloric acid and water contain, as I have said, hydrochlorate of aniline and red dye. They are precipitated by an alkali, and aniline, which may be purified by distillation, is thus recovered.

300

Specification in pursuance of the conditions of the Letters Patent, filed by the said Charles Adam Girard in the Great Seal Patent Office on the 12th July, 1861. "This invention has for its object improvements in preparing colouring matters for dyeing and printing. For these purposes I take red aniline dye, a substance now well known, and which is prepared from aniline, or more commonly from a mixture of aniline with its homologues, and which may be prepared from the homologues of aniline, and this dye having been purified in the usual manner, is mixed with a quantity of aniline. The proportions which I prefer to employ are about equal quantities by weight of aniline or its homologue and of red aniline dye. The mixture is maintained for several hours (say about five or six) at a temperature between 155° and 180° (centigrade), and as nearly as possible to 165. The substance, which is now violet, is boiled with a mixture of water and hydrochloric acid, say ten or twelve parts of acid to one of the substance, the acid being mixed with a large quantity of water, and the boiling is continued until the washing is complete. The excess of aniline and of red dye which has not been transformed is dissolved, and a violet residue remains. This residue is completely soluble in alcohol, acetic acid, wood spirit, and boiling water slightly acidulated with acetic acid. All these solutions may be employed directly for dyeing violet. In order to obtain the blue dye the violet mass is boiled several times with hydrochloric acid diluted with a small quantity of water, say ten parts of hydrochloric acid of commercial strength to one hundred parts of water, and then washed with boiling water, the boilings being continued until the operation is complete, as will be readily ascertained from the appearance of the dye. The substance thus obtained is a blue, having a beautiful coppery lustre. To employ this colour in dyeing it is sufficient to dissolve it in concentrated acetic acid, alcohol, or wood spirit, and to dilute these solutions with a convenient quantity of water. I would state that liquids obtained by treating the violet mass with hydrochloric acid and water contain hydrochlorate of aniline and red dye: they are precipitated by an alkali, and aniline, which may be purified by distillation, is thus recovered. I would also remark that, in place of first preparing a red dye and purifying the same, a similar result may be obtained by treating aniline with reagents, such as are ordinarily employed to convert it into red dye, but using an excess of aniline, so that the first action is to convert a part of the aniline into red dye, and then, the heat being maintained as hereinbefore mentioned, the excess of aniline converts the red dye into the violet substance; I prefer, however, to conduct the process in the manner first described.

"Having thus described the nature of my invention, and the manner of performing the same, I would have it understood that what I claim is the treating red aniline dye with aniline or its homologue so as to transform it into other dyes, as hereinbefore described."

Class

Dublin International Exhibition, 1865.—On Wednesday evening last Sir Robert Kane delivered a lecture at the Society of Arts "On the Recent Progress and Present State of Industry in Ireland, and the Dublin International Exhibition of 1865." The meeting was exceedingly well attended; and the prospects of the coming Dublin Exhibition look remarkably promising. We may inform our readers that the arrangements of classes will be the same as at the London Exhibition of 1862. A, section 2, will comprise chemical and pharmaceutical processes and products generally; and a section of Class B will include philosophical instruments and processes depending on their use, photographic apparatus, surgical instruments, &c. All these manufactures, we should hope, would be well represented from England. One of the Committee, who has visited all the principal seats of industry on the Continent, has returned with flattering

CHEMICAL NEWS, Dec. 17, 1864.

promises of support from the manufacturers, and great encouragement from the various governments. The building, we may state, is already approaching completion; and the Exhibition will open on Tuesday, May 9. A London Committee of Advice, of which Mr. P. L. Simmonds is secretary, sits at the house of the Society of Arts, from whom any information that intending exhibitors wish for can be obtained.

Serious Case of Poisoning.-We are happy to be able to state that the case of poisoning at York, related under the above heading in our number for December 3, has been shown to be simply the result of an excessive dose of morphia, and not the consequence of a mistake on the part of Mr. Hardman's porter. Dr. Proctor, who has been kind enough to forward us his evidence at the inquest, made a post-mortem examination of the body and an analysis of the contents of the stomach. In the latter he discovered no other poison besides morphia, which it was known the deceased had long been in the habit of taking. The heart of the deceased showed signs of fatty degeneration, and the verdict was death from that cause, accelerated by an overdose of morphia taken voluntarily.

Actonian Prize Essay of 200 Guineas.-Attention is directed to the following advertisement, which appeared in the Times of May 28, 1863. It will be seen that the latest period for the acceptance of the essays is fixed at a fortnight from the present date.

(Copy.)

"ROYAL INSTITUTION OF GREAT BRITAIN, ALBEMARLE STREET.-The next Actonian Prize or Prizes will be awarded in the year 1865 to an Essay or Essays illustrative of the Wisdom and Beneficence of the Almighty as manifested in any of the Phenomena of Radiation. The prize fund will be 200 guineas, and may be awarded as a single prize, or in sums not less than 100 guineas each, or withheld altogether, as the Managers in their judgment should think proper.

"Competitors for the prize are requested to send their Essays to the Royal Institution on or before ten o'clock p.m., December 31, 1864, addressed to the Secretary; and the adjudication will be made by the Managers in April, 1865. "H. BENCE JONES, Hon. Sec., R I. "May, 1863."

ANSWERS TO CORRESPONDENTS.

In publishing letters from our Correspondents we do not thereby adopt the views of the writers. Our intention to give both sides of a question will frequently oblige us to publish opinions with which we do not agree.

All Editorial Communications are to be addressed to the EDITOR, and Advertisements and Business Communications to the PUBLISHER, at the Office, 1, Wine Office Court, Fleet Street, London, EC.

Leather Dresser.-There is no work which we can recommend you. Dr. Adriani.-It is obviously only an abstract, but it is all that has reached us.

J. Sutcliffe-It can only be procured in a volume with the rest of the reports.

J. B. Pearse, United States Army Laboratory.-There is great difficulty in procuring the work, but we will do our best for our correspondent. J. J.-Zinc-ethyl, but it must be sealed in a tube. Lead pyrophorus, a powder, will do as well, and is much more easily procured

Kamptulicon. The material to which you refer is a combination of cork raspings and india-rubber. You are mistaken in supposing the latter to be in the vulcanised condition, for on digesting with coalnaphtha the rubber is easily dissolved, and its proportion may be ascertained by recovering it from the filtered solution on the evapora tion of the solvent, or indirectly by weighing the cork.

A Brazier.-Common brass always contains lead, and sometimes a little tin, in addition to copper and zinc. The composition of the best sheet-brass varies from 66 to 70 per cent. of copper, the rest being zinc. There can be no doubt that the addition of iron does confer increased strength, but there is then a liability of the alloy rusting by exposure. For further particulars, see "Percy's Metallurgy," Vol. I.