The part of the building devoted to the display of English-made chemicals is situated in the south gallery, slightly west of the transept, and is bounded on the east by a collection of Paisley silks, and on the opposite side by the space given over to the various foodstuffs used in England.
There is also a superb chemical trophy in the nave. A great variety of chemical and pharmaceutical preparations are further dispersed in the various parts of the building devoted to the industrial products of foreign countries and in those where the English colonies are represented.
If, after ascending the staircase which lies a little to the west of the transept, one proceeds to the end of the section, along the south wall, one will not fail to admire a display of a great variety of colours and very fine chemicals, from the Millwall factory, conducted by Messrs. Pontifex. The most striking objects in this collection are the beautiful crystals of tartaric acid, a substance which the cotton printers of the north of England employ by the thousands of barrels, apart from the quantities demanded by medicine and pharmacy, by the manufacturers of lemonade, degingerbeer, and other refreshing drinks which have become so popular of late years during the summer months.
This acid is derived from argol or raw tartar, which is deposited in the casks during the fermentation of wine. England receives every year considerable quantities of this crude substance, which are sent to her from Naples, Marseilles, and other vinous countries.
These two substances, as they differ very little from each other in their composition, contain a large proportion of bitartrate of potash. The acid is easily separated from this alkali by chemical means, and it is crystallised by boiling and delivered to the trade.
However, a single crystallisation is not sufficient to give it the perfect whiteness or rather the great transparency which the specimens exhibited possess, because the solution is always more or less tinged with matter from the grape: but this matter is then separated by filtering the boiling solution through very divided animal black. In the northern part of the watch is a lead vessel containing some fine crystals of citric acid, which is extracted from lemon juice or silt, and which is then filtered out of the solution.
lemon juice or lime, and which is used in the preparation of the same drinks as tartaric acid. However, as the properties of citric acid differ in many respects from those of this chemical agent, it is applied to many uses where tartaric acid is rejected.
We still find there, not only specimens of copper sulphate or blue couperose, which the manufacturers of colours employ in quantity, but also sulphate of potash, a secondary product of the manufacture of tartaric acid. This salt is sometimes used in medicine, but most of it is converted into alkali carbonate.
On the shelves are exhibited all sorts of colours prepared for the use of the painter and the wallpaper maker, together with a series of models showing the smelting and refining of lead ore and its transmutation into ceruse.
Opposite this collection is a very fine group of crystals of acetate-or as it is more commonly called lead sugar-from the Melincrythan Chemical Works, and a case of extremely pure chemical reagents prepared by Mr. Burton of Holbornbars, for use in scientific chemistry. One acetate of lead is obtained by saturating the oxide of lead or litharge, with acetic acid produced, either by the acetic fermentation of saccharine liquors, or by the distillation of wood. This article is mainly used for the preparation of dyes or colours.
Nearby is a series of specimens sent by the trustees of the J. Buckley estate of Manchester, showing the processes employed in the manufacture of alum and iron sulphate or green couperose; these specimens begin as blocks of aluminous shale, and end up as beautiful crystals of both substances. Both alum and couperose are widely employed in dyeing and the manufacture of colours; but considerable quantities are also employed in the preparation of ink and in giving a black tint to leather. Other sets of specimens, indicating this manufacture, were sent by Messrs. Wilson of Glasgow, Mr. L. Spence, from his Pendertou Alum Factory, Manchester, and Mr. P. Moberley of Land's end, near Whitby.
Some specimens of cannel-coal, and the products made from it, are still to be seen here. The latter have been sent by the preferred gas company, and contain naphtha in its various transformations, as well as magnificent samples of naphthalene preserved under glass globes. Attention is then drawn to the beautiful crystals of dichromate and prussiate of potash exhibited in the compartment of Messrs Dentith and Co.
The first of these substances is almost exclusively employed in the preparation of the various red and yellow lead chromates; and the second, which is prepared by means of the calcination and leaching of animal substances, such as the horn and hoofs of quadrupeds, is chiefly employed in the manufacture of the various Prussian blues which are used in such large quantities by painters, canvas printers, and manufacturers of wallpaper.
We then find samples of ultramarine and the various dyes used by the dyers of cotton, canvas, silk, and wool. In the southern part of the counter is a compartment containing a superb pyramid of copper sulphate, from the workshops of Messrs. Hahmel and Ellis, of Manchester.
This collection also contains some specimens of lead nitrate, which are really remarkable, and sulphur in its different periods of preparation; and various ammoniacal salts taken from the waste water which occurs in abundance during the manufacture of coal gas.
Our attention is immediately fixed on samples of a new colouring matter, called lead oxichloride, prepared, according to a patented process, by Mr. H. L. Pattinson, of Newcastle-on-Tyne, who derives this colour directly from lead sulphide or common galena. It is evident that this circumstance alone enables the new product thus obtained to be manufactured under much better conditions than ordinary ceruse, which must not only be prepared with metallic lead, but must remain exposed for about three months to the vapours of acetic and carbonic acid in the tan layers where it is formed. However, the colour of this substance is not quite as intense as that of good quality lead carbonate, and its properties, with regard to strength and yield, have not yet been established by experiment. There is every reason to believe, however, that the test will be satisfactory.
The counter on the left is occupied by Messrs. Howard and Kent of Stratford, who exhibit a great variety of extremely pure and beautifully crystallised substances for use in medicine and the arts. Among these substances may be mentioned camphor, borax, tartaric and citric acids, and various preparations of antimony, silver, bismuth, mercury and iron.
In a watch against the southern wall is a collection of foreign barks and the various alkaloids and salts extracted from them. Among the preparations of this class, the watches of Messrs. Spencer and Sons offer fine samples of theine and caffeine, and those of Messrs.
and caffeine, and those of Messrs. Hemingway contain superb samples of organic double salts.
Messrs. Tennant and Co. of Manchester exhibit salts of copper, zinc, tin, potash, and soda, as used by the cotton printers of this neighbourhood. Mr. G. Young, of Ardwick-bridge, exhibits samples of "paraffin," mineral oil, and stannate of soda, together with an explanatory model of the processes, recently patented, which this skilful chemist employs to extract this salt directly from the tin ores of Cornwall.
Against the south wall is a small display case containing specimens of deeds, writings, books, engravings, and maps, which have been altered by age, smoke, steam, or fire, and subsequently restored by a process of the invention of Mr. George Clifford of the Inner Temple. Amongst these restorations we notice with particular interest portions of deeds, etc., torn from the great fire of Lincoln's-Inn, and whose fragments, sometimes entirely discoloured, have been made perfectly legible by this process.
Here again is a display of the processes for the manufacture of zinc oxide, or zinc white, the use of which is becoming so widespread in place of ceruse, which was formerly employed exclusively by painters for the preparation of white colour. This substance is obtained by exposing molten zinc to a current of air, in special furnaces, built of refractory bricks, and which are given more or less the shape of the retorts for the manufacture of coal gas. Zinc, which is an extremely volatile metal, combines with the oxygen in the heated air to form the white oxide of this metal, or the "nihil album" of the ancient alchemists. This flaky product is then conducted into a series of chambers prepared for its condensation; there it is taken up in a suitable state to be mixed with refined linseed oil and applied immediately as paint. The colour obtained by this process has the advantage over ceruse of not being attacked by the hydrogen sulphide gas which promptly gives a dark brown or black tint to bodies which are covered with ordinary paint; it is therefore perfectly adapted in all cases where lead oxide paint would be exposed to this drawback. There are, however, certain circumstances which seem to indicate that this substance cannot always be of so economical use as the lead compounds which have hitherto been employed in the decoration of the frames of our houses.
Zinc oxide, though of a beautiful white colour, has unfortunately a certain transparency which, in equal proportions, prevents it from covering the object to be painted as well as its happy competitor. There is another difficulty with the use of zinc oxide: without the addition of a suitable drier, it remains on the wood for a long time before it acquires the necessary hardness to be covered with a second coat. Now, most of the compositions sold under the name of patented driers, containing lead, their mixture with zinc white, gives the latter the property of blackening when exposed to the vapours of hydrosulphuric acid, and also deprives it of one of its most valuable qualities. It is to be wished that the resources of modern
It is to be wished that the resources of modern chemistry will at last find the means of remedying this disadvantage, for ceruse exerts such a fatal influence on the workmen employed in its manufacture, and on the painters who apply it, that the discovery of a substance of such low price, and which would replace it with advantage, would be an immense boon to both classes of workers.
Some of the zinc colours which accompany the other specimens are also very beautiful and will soon, no doubt, come into general use.
Returning to the line of counters, the attention of visitors will unerringly be directed to a large cake of ammonia salt, or hydrochlorate of ammonia, and admirable crystals of nitrate of potash, exhibited by Mr. F. Hill of Deptford. Magnificent crystals of the same substance from the factory of Messrs. Richardson Brethren, of London, are also exhibited next to specimens of saltpetre, charcoal, and sulphur, which have been ingeniously arranged, to show how gunpowder is made at the famous mills of Waltham Abbey.
There are also enormous crystals of soda ash, which, when exposed to an atmosphere of carbonic acid, have been converted externally into a bicarbonate of that alkali. At the same time we may mention some fine crystals of soda ash exhibited by Mr. Cook, of Newcastle-on-Tyne. This substance was formerly obtained by leaching certain species of kelp which were collected in various localities for this purpose. Two kinds of this coarse soda were known on the market, which were called "barilla" and "common soda".
The former is the half-melted ash of the "soda salsola," which grows on the Spanish coasts of the Mediterranean, in the vicinity of Alicante; and the latter is the calcined ash of certain "fucus," such as the "seratus," the "digitatus," the "nodosus," and the "vesiculosus," which are found on many of the rocky coasts of Brittany, where they used to be collected in order to extract the alkali which they contain.
But today the immense quantities of soda ash annually employed by various manufactures, such as those of soap and glass, and the no less considerable masses of this substance which are consumed for domestic purposes, are exclusively derived from common salt, which chemists call chloride of soda.
This product, which occurs in a native state in many countries of the world, abounds particularly in Cheshire, where it is first converted into sulphate of soda by the addition of a certain quantity of sulphuric acid, better known as vitriol. The sulphate of soda thus formed is then ground with its weight of lime (carbonate of lime) and half its weight of pulverised coal. The mixture thus prepared is then heated strongly in a reverberatory furnace, which chemically determines the production of lime sulphide and soda ash, which is then dissolved in water and crystallised, in the form in which it is found in commerce today.
The extent of this manufacture in Great Britain, and its importance as a source of our commercial wealth, will be justly appreciated when it is known that the annual production of this country probably amounts to not less than 200,000 barrels, and that in 1850 the exports alone amounted to 44,407 barrels with a declared value of 10,055,800 francs.
In this part of the section there is a display case, in which Mr. Windsor and Mr. Newton have exhibited some very fine colours for artists, and a collection of brushes, palettes, and other accessories indispensable to the painter's studio. Nearby are samples of colours, both for the artist painter and the wallpaper maker, from the factory of Mr. Blundell and Mr. Spence of Hull. There are also samples of white lead oxichloride, zinc white paint, new drying oil, corrosive and stucco paints, and a composition to prevent the keel of ships from rotting and sticking.
On the adjoining counters will be found several preparations of great beauty, including naphthalene, quinine, caffeine, and salts of morphine, beberine, and other alkaloids.
Messrs. Huskisson exhibit some fine specimens of the preparations of soda, iodine, mercury, potash, and lead; together with beautiful crystals of various organic acids.
Nearby are samples of fine colours, manufactured by Messrs. Godfrey and Cooke, and containing very fine carmine, and a species of lacquer soluble in ammonia, and chiefly employed in the preparation of coloured papers.
Among the pharmaceutical preparations one will find, not only a numerous and varied collection of foreign drugs, but also the beautiful preparations and compositions obtained from them by chemical treatment.
In this class we find jalap, saffron, kuso, Indian bael, Bengal quince, soap berries, jujubes, rhubarb, aloe, sarsaparilla and many other similar products. Amongst the prepared products are those exhibited by Mr. M'Farlane, of Edinburgh, showing the manufacture of Morphine salts, together with that of gallic acid, and specimens of beberine from the bark of the u green heart. "Samples of cantharidin, the vesicatory principle of cantharide, will excite much curiosity here, as will bottles of aloin, the base of aloe, and crystals of mannite of peculiar beauty.
The collections of chemicals are not very numerous in the other parts of the exhibition, but some foreign nations have exhibited considerable quantities of drugstuffs and chemicals. France sent alum,
copper sulphate, prussiate of potash, sulphate of potash, iodides, sublimed iodine, potassium chloride, varnishes and gelatine.
In the same division we also find acetates of lead, soda, copper, ceruse, rectified alcohol and therabentine.
Austria has common salt, cream of tartar, acetate of soda, chloride of lime, acetic acid, arsenic, potassium chloride, mercury compounds, oxides of chrodium and uranium. Albumen, prussiate of potash, stannate of soda, chromium yellow, ultramarine, and yellow cadmium may be added to this list. The same country sends soap, litharge, minium, vermilion and one hundred and eighty samples of fine colours, including lacquers and carmines.
Germany exhibits chloroform, sulphuric ether, concentrated acetic acid and many other chemical products of all kinds.
From Portugal and Madeira, tartaric acid, raw tartar, sodium sulphate, barium nitrate, strontium nitrate, lead nitrate, zinc sulphate, potassium acetate, refined saltpetre, zinc oxide and potassium carbonate were received. Iron sulphate, corrosive sublimate, red oxide of mercury, lavender oil and concentrated alcohol are also found in this division.
Sardinia exhibits specimens of ceruse, soda, soap, nitric and sulphuric acids, baryta nitrate, gallic acid, quinine sulphate and citrate, stearic acid, iron sulphate, copper sulphate, alumina sulphate and various other substances.
Tuscany supplies chemical glass apparatus, and some chemical products, among which we shall mention rock salt, alum, sulphur and preparations of quinine and santonia, with some mercury compounds and boric acid.
The department assigned to the Indian Archipelago contains some specimens of aloe, agaia wood, eagle wood, sagah bark, sapwood bark, mango bark, with a collection of gums in small bottles, and pearl seeds which the Chinese use as medicine.
New Zealand has sent specimens of wood used for tanning, and soap made in the colony.
In addition to the above, there are a number of very fine and rare items scattered throughout the building. But as we intend to give from time to time a series of articles on the chemical and pharmaceutical products of the World's Fair, we defer to a future occasion their particular description and the examination of their various qualities.
© Palais de Cristal – Journal Illustré de L’Exposition de 1851