MR. AIKIN'S ILLUSTRATIONS OF ARTS AND MANUFACTURES.

" IN the year 1828," says Mr. Awn; in his preface, " it was pro- posed to the Society of Arts to appropriate a few evenings to the illustration of the Arts and Manufactures of Great Britain." The plan was approved of, and a Committee appointed to carry it into effect. All the papers read during the first two years were fur- nished by Mr. Anus, who was then Secretary to the Society ; after which period, other members " were prevailed on to give illustra- tions of those arts and manufactures with which they were per- sonally conversant, and the plan has been kept up with spirit to the present time." The papers furnished by Mr. AIKIN exceed forty ; some of which have been published in the transactions of the Society, whilst some continue in manuscript. The volume be- fore us consists of a selecOon from the whole of these papers ; sub- jected to extensive revision, and illustrated by engravings, to supply the place of the actual articles exhibited to the meeting, which articles were supplied by members of the Society or by public institutions. The papers an Mr. Amm's volume are fourteen, illustrating eleven subjects; some pure manufactures—as Paper and Pottery, Felting and Hatmaking; others, natural productions, whose sub- stances, though modified or changed by art, and so far manufactured, are still homogeneous bodies—as Bone, Horn, Tortoiseshell, and Whalebone ; in both which departments of trade skill only prepares and fashions the natural substance ; whilst in Gypsum, Limestone, and Calcareous Cements, the nature of the primitive body is alto- gether changed. Engraving and Etching is a pure art. The four papers devoted to Iron embrace the history of its use, (from. which Mr. SCRIYENOR seems to have borrowed pretty largely,) and an account of the modes of its manufacture. Furs and the Fur-trade is a piece of commercial history. Varying in attractive powers as regards the character of their subjects, and perhaps in relation to the interest which the reader may feel in them from previous circumstances or practical know- ledge, the whole of these papers display considerable ability. The volume abounds with conclusive facts bearing upon the matter in hand, clearly and orderly presented. It also displays considerable reading upon the subjects the writer intends to illustrate, as well as a sufficient knowledge of the practice. But the Illustrations of the Arts and Manufactures of Great Britain is something more than a vehicle for conveying recorded or floating knowledge bearing upon the useful arts. The volume has a tendency to elevate the character of the humblest handicraft, by showing how its successful practice must be based upon philosophical principles; whilst it indicates the practical uses to which the results of the highest, and what seems a priori the most transcendental investi- gations into nature, may be applied ; manufactures, like all other arts whether the fine or the liberal, being but a judicious following of nature.

One of the most striking features of Mr. Anus's volume is the use to which science and civilization turn things appa- rently the most worthless. Dry bones, in the opinion of our ancestors, were not only useless, but they gave rise to a phrase which embodied uselessness in a metaphor. But the philosopher comes with his accumulated knowledge and his experiments, and see what value science adds to old bones.

CHEMISTRY ON BONES.

The decomposition in close vessels of the single substance bone, produces five new substances ; namely, animal charcoal, carbonate of ammonia, animal oil, water, and inflammable gas. A. low red beat volatilizes all these substances except the first ; which, therefore, when the process is performed on a large scale in iron vessels, remains in the retort separated from the other four com- pounds. The water, the carbonate of ammonia, and part of the oil, are con- densed and remain in the receiver ; the inflammable gas, holding in solution another part of the oil from which it derives an inconceivably nauseous odour, passes off through a pipe, and is either conveyed into the ash-pit of the furnace, whence it is drawn up among the burning fuel and is consumed, or is set fire to as it issues from the mouth of the pipe ; by either of which methods its noisome smell is for the most part avoided. The ammoniacal liquor likewise combines with a little of the oil, from which it may for the most part be se- parated by redistillation: enough, however, of the oil remains united with it to produce that particular modification of odour by which spirit of hartshorn (for so this substance is commonly called) is distinguished from pure ammonia ; or, by other processes unnecessary here to mention, the ammonia is obtained entirely free from the oil. I now return to the animal charcoal, which I have already briefly mentioned. When obtained from bone, it is called bone-black ; when from ivory, ivory- black ; the difference between these two being merely that of texture and some slight tint of colour, for they both are an intimate mixture of carbonate and phosphate of lime with charcoal, resulting from the decomposition of animal matter. Till of late, the only use to which this substance was put was the basis of black pigments; ivory-black having been first so applied by the cele- brated Greek painter Apelles. Some years ago, a German chemist of the name of Lowitz, settled at Peters- burg, discovered that common charcoal when fresh burnt and in fine powder has the property of taking away the colour of common vinegar and of several other liquids, and likewise of removing the odour proceeding. from vegeta- ble and animal substances in a state of spontaneous decomposition. This in- teresting and valuable fact was soon applied to the clarification of various liquors in pharmacy, and as an auxiliary in the art of refining sugar. About the year 1811, M. Figuier of Montpellier ascertained that charcoal from animal substances not only is equally efficacious when used in considerably smaller proportion than vegetable charcoal, but that it is capable of decolonring many liquors on which the latter has no sensible effect whatever. This discovery created immediately a demand for bone-black in this country and in all the other manufacturing countries of Europe ; those especially in which refined sugar is obtained either from brown cane-sugar or from the juice of the beet. It is not only in one kind of industrial pursuit, however, that old bones are available. Returned to the dust whence they came, they increase the produce of the land, and in one article of culttva- tion may be said to act as a medicine, carrying the, crop over a crisis ; properly boiled, they may be used as food, and excellent soup they make ; their shavings provide the delicate and the refined with an article of luxury; and the commerce in bones is now carrying ships round the world.

BONE SOUP, WITH A HINT FOR THE BESIEGED.

The solid part of the long bones contains very little soluble matter : it would therefore, in most cases, be a matter of economy to exclude them, the advantage to be derived from them by ordinary treatment not being equal to the value of the fuel which they would require. It is from the enlarged ex- tremities of the long bones and their articulating surfaces that the principal supply of nutritive matter is to be derived : these parts, therefore, should be sawed off from the rest, and be broken into pieces. From the bones of young animals thus treated, boiling water will, in two or three hours, extract the whole or nearly the whole of the soluble matter : but in the bones of older ani- mals, the gelatine seems to be in a state of condeosation approaching to that in which it exists in skin, and therefore requires the long-continued action of boiling-water for its separation. By way of experiment, I had the leg-bone of an ox sawed longitudinally and boiled for three or four hours. At the end of this time, the whole of the fat and mucus had been extracted, with part of the jelly. On applying the finger to the cellular part of the bone when wiped dry, I found the surface to be considerably sticky ; and on examining the cells, I found many of them completely filled with a transparent substance, scarcely viscid, but much resembling pieces of glue that had been put to soak in cold water ; by which, as every one knows, the glue swells exceedingly by absorp- tion of the water, without, however, becoming viscid. A second boiling for three or four hours in fresh water dissolved out a considerable portion a the gelatine • but still the surface of the bone remained sticky, many of the cells had a glazed surface, and even after a third repetition of the boiling only a few even of the superficial cells were quite empty. It is evident, therefore, that we cannot avail ourselves, with any regard to economy of fuel, of the whole of the nutritive matter contained in bones by the action of boiling -water applied in the common way. But by means of a digester—that is, a boiler with a steam- tight cover and a safety-valve—we can without hazard raise the temperature of water from 212 degrees, its boiling-point in the open air, to 270 degrees or 280 degrees. At a less heat than even the former of these, not only the con- densed gelatine, but also the membranous part of bones, is dissolved, if the bones have previously been reduced to small pieces ; and the undissolved residue will be found to be a friable crumbling mass, with scarcely any remains of animal matter. It appears that bone-soups are thus prepared at present at some of the hospitals and military head-quarters in France, and memoirs have been pub- lished stating the advantage of making a collection of dry bones as part of the provisions of a garrison in case of siege, being a kind of food scarcely suscep- tible of decomposition or of destruction by rats or mice, and which would re- quire no other magazine than simply making them into stacks and covering them with a roof of thatch or any other material.

BONE JELLY.

The scrapings, shavings, or sawdust of hone, is an article that bears a good price in the market, being much used by inistrycooks and others as a material for jelly, which it readily gives out to boiling-water. The jelly thus produced is probably quite as good as that from calf's foot ; and the shavings, when dry, have the advantage over calf's foot of not suffering any change by keeping. Another use of considerable importance to which bone-shavings are applied, is in case-hardening small articles of steel.

BONES AS MANURE.

Bones have always been used as one of the ingredients of that multifarious mixture of offal of all kinds a dunghill; but it is only of late years that their extraordinary value as manure has been fully ascertained. About forty years ago, an acquaintance of mine was cultivating a small estate of his own ; and from not having been originally brought up to farming, was the more ready to try novel experiments. A pack of hounds was kept in his neighbourhood; and this furnished him with an opportunity of obtaining at small cost the bones of the old horses and other animals that were slaughtered for food to the dogs. Be invented, or got made for him, a machine for crushing the bones; and then spread them as a top-dressing on a grass field, the soil of which was a sour red clay, that produced nothing; but dyers' broom and the other weeds that usually grow on such soil, along with the coarsest grasses. The effect produced by the bones was strikingly evident in the next spring ; the dyers' broom and other weeds had mostly disappeared, and were succeeded by a close undergrowth of clover and fine grasses. The animal matter of the bones no doubt contri- buted much to this striking amelioration ; but the earth of the bones, especially the phosphate of lime, also bore its share in it." I do not know if bones are valued as a manure in any part of the Continent of Europe; but it is certain that of late years they have attracted in a very particular degree the attention of the English farmer. Bones are collected in the streets of London and other great towns, and after being sorted, those that are not required for other purposes are used as manure. In the Thames, above London Bridge, may almost always be seen a few sloops and cutters, chiefly from Hull, which are occupied in this trade. They take the bones on board generally in a more or less putrid state, and stow them in bulk in the hold: here they soon begin to ferment, giving out an odour by which the bone- ships are detected at a considerable distance ; and when the cargo is discharged at Hull, it is frequently reeking and smoking hot from decomposition. This probably softens the texture of the bones, and renders them more easy to be crushed in the mill through which they are passed previous to disposing of them to the farmers. They are employed chiefly in two ways, either as a top-dressing to grass-land or drilled with turnip-seed; the plants from which, under the stimulating effect of this powerful manure, quickly pass through their first stage into the rough leaf, and thus in a great measure avoid the attacks of the fly and other insects, by which young turnip-plants of tardy growth are often entirely cut off. Our native supply of bones is not at present sufficient to answer the large and increasing demand for them for agricultural use ; and bones are now imported from South America and other parts. It is even said that some of the celebrated battle-fields of our own time have furnished con- siderable supplies of this now valuable commodity. Of the other papers, those on Furs and Hatmaking strike us as being the most interesting. The chapter on Furs and the Fur- trade contains a pleasant antiquarian account of the uses of furs, a rapid summary of the countries which produce them, and a good précis of the present trade. The chapter on Hats may be in- stanced as a very skilful and happy exposition of manufacturing manipulation, as well as of the principles on which it rests. From these two valuable papers we will select a few extracts.

ENGLISH FOB.

One fur, and one only, is peculiar to England, namely, the silver-tipped rab- bit of Lincolnshire. This fur is a dark or lighter gray, mixed with longer hairs tipped with white. It is little used in this country, but is readily purchased abroad, especially in Russia and China. In assorting it for these markets, it is, however, necessary to be careful with respect to the colour; for while the Rus- sian wideagerly purchase the dark-coloured skins, he makes no account of the gray ones. The Chinese are equally fastidious but their taste happens to be the reverse of the Russian& Thus the fur-merchant, to dispose of his coin-

modifies to the best advantage, must be familiar with the caprices of fashion on the other side of the globe ; I say the caprices, because a few years ago none but dark skins were saleable in China.

DRESSING TOES.

The American furs come in their raw state, that is, merely dried : they are dressed here by treading them with refuse butter, which makes the skin supple and not liable to break or tear ; but as this cannot be done without also greasing the hairs, it is necessary, after treading, to turn them for some time in a revolving barrel set on the inside with spikes, and containing chalk, gyp- sum, or sawdust, which absorbs the superfluous grease.

HISTORY OF HATS.

The use of hats, that is of caps with brims to them, is of a very ancient date. Among the Greeks, the Dorian tribes, probably as early as the age of Homer, were characterized by the broad-brimmed hats which they wore when on a journey. The same custom prevailed among the Athenians, as is evident from some of the equestrian figures in the Elgin Marbles. The Romans appear in general to have used no covering for the head except a corner of the toga or upper garment ; but at sacrifices and festivals they wore a bonnet or cap; and this being permitted only to freemen, part of the ceremony of manumit- ting a slave consisted in putting one of these caps on his head. But on a journey the Romans were accustomed to wear a hat called petasus, with a margin wide enough to shade their faces from the sun.

In the middle ages, the bonnet, or cap with a narrow margin in front, ap- pears to have been in use among the laity, while ecclesiastics wore hoods or cowls; but Pope Innocent the Fourth, in the thirteenth century, allowed to the cardinals the use of scarlet hats. About the year 1440, the use of hats by persons on a journey appears to have been introduced in France, and soon became common in that country, whence probably it spread to the other Euro- pean states. The cap of the ancients was certainly made of wool ; and this, as well as the hat, was probably knit. I do not know when felt was introduced as a material for bats, but it is stated that the hat worn by Charles the Seventh of France, on occasion of his triumphant entry into Rouen in 1440, was of felt.

ORIGIN OF FELTS.

Concerning the origin of felt little is recorded, and that little is perhaps not greatly to he depended on. A person, some call him a monk, having used some carded wool by way of socks, found that the fibres by long friction between the foot and the shoe had matted together so as to produce a firm texture like cloth, and from this hint arose the manufacture. Specious as this account or tradition may appear to be, it deserves to be remembered that the Turcomans from time immemorial have inhabited tents covered with black or white felt, and that some of the wanderers among the Crusaders may have brought the art of felting from Asia to Europe. In order to understand the mechanism of felting, and to qualify us to judge of the efficacy of the processes by which it is brought about, it will be necessary to enter into some preliminary inquiries respecting the structure of hair and wool.

ENGLISH HATS.

Hats are worn in this country by people in every rank of society ; and till within the last thirty or forty years the only essential difference between them was in quality, and consequently in price: the most costly being made of the finest materials and by the best workmen, while the cheaper ones were of inferior materials and by inferior workmen. Of late, however, the increased price of bea- ver has led to the substitution of silk for the roughing or nap of felt hats; and a diminution of weight has still more recently been obtained by the substitu- tion of silk or hemp as the material of the body of the hat. We may there- fore distinguish five kinds of hat,—the beaver hat, of which the body is felt and the nap of heaver; the plate hat, with a body of felt and a nap generally of musk-rat, neuter, or some other inferior fur ; the felt hat, with a body of felt and without any nap ; the silk hat, with a body of felt and a nap of silk plush; and lastly, a hat with a body of hemp or waste silk and a nap of silk plush.