BOMBAZINE (from the Greek Bóμßug, a silkworm). A fabric of worsted and silk, the warp being of silk, and the weft or shoot of worsted.

BONE is formed of a dense cellular tissue of membranous matter, rendered stiff and rigid by insoluble earthy salts, of which phosphate of lime is the most abundant. The proportions of earthy and animal matter vary greatly with the kind of bone, and with the age of the individual, the bones of an adult been richer in earthy salts than those of an infant. The following comparative analysis of human and ox-bones will show the nature and amount of the constituents :

The teeth have a similar composition, but contain less animal matter, so that their texture is more solid and compact than bones. The enamel does not contain more than 2 or 3 per cent. of animal matter. If bone be digested in very dilute muriatic acid, a moderate degree of effervescence will take place in consequence of the presence of carbonate of lime. In some days all effervescence and chemical action will cease, and that which remains undissolved will still represent the size and form of the original bone, but its appearance is changed, for it is semitransparent, cellular, soft, flexible, and to a certain extent elastic. If this be washed and boiled in water, a portion of it will dissolve, and the solution, boiled down to the proper consistence, will become viscid and gelatinous on cooling, and will dry into a hard glue. If again dissolved in water it will become curdy, and give a grey precipitate with solution of nutgalls, and exhibit all the properties of gelatine. The remaining portion is insoluble in water; it becomes hard and somewhat brittle in drying, and burns like horn. Dissolved in caustic fixed alkali, it forms a soapy liquor, and exhibits all the other properties of albumen or membrane. The acid solution in which the bone was steeped will on the addition of caustic ammonia give an abundant precipitate of phosphate of

Fat, although usually present in bone, is not an essential part thereof. The horn of the stag and of other animals of the same kind is entirely free from fat; hence, hartshorn jelly, made by boiling the shavings of stags'-horn in water, is often recommended to persons of very weak digestion in preference to other animal jellies, as being absolutely free from oil; for although hard fat will not combine with jelly, yet the softer oily fats will do so in small proportions.

All animals that eat flesh, also eat bones if of a size to be easily crushed and masticated. The richness of meat soups is increased by boiling the bones with the meat, but in this way only a small portion of the food contained in bones is made available; a part of the gelatine is with difficulty, and the membranous part not at all, soluble in common boiling water. Much of the fat locked up in the cells of the bone cannot escape unless the cells be broken into. The solid part of the long bones contains, however, very little soluble matter; but their enlarged extremities and articulating surfaces afford the chief supply of nutritive matter. These parts should be sawed off, and the rest broken to pieces. The bones of young animals thus treated will in the course of two or three hours yield most of their soluble matter to boiling water; but in the bones of the older animals the gelatine seems to be in a state of condensation approaching that in which it exists in the skin, and therefore requires the long-continued action of boiling water to separate it. By means of a digester, or boiler with a steam-tight cover and safety valve, the temperature of the water may be safely raised to 270° or 280°, but at a less heat than this the condensed gelatine and membranous portion of the bone become dissolved if previously reduced to small pieces. The insoluble residue will be found a friable, crumbling mass, with scarcely any remains of animal matter. Bone soups are prepared in this way at the hospitals and military head-quarters in France, and it has been proposed to make a collection of dry bones a part of the provisions of a garrison in case of siege. If formed into stacks covered with thatch, they would be imperishable, and not be exposed to the attacks of mice and rats. The only objection to bone soup is that it sometimes has a burnt flavour, but it has been proposed to get rid of this by first digesting the bones in dilute muriatic acid in a stone trough until the earthy matter is dissolved out; then wash the membranous portion now left in an abundance of water; and lastly, sprinkle it with a little soda to get rid of all traces of the acid. By exposure to the air the membranes will dry to a horny texture without any fear of decomposition; and this can be more easily converted into a palatable food than by cooking the entire bone.

In Norway and Sweden, in times of scarcity, fishbones, such as those of the mackerel, browned on a gridiron until they become friable, and, eaten with pepper and salt, form a palatable food.

BOOKBINDING. The demand for books at the present period of our history, so greatly exceeding that of any former time, has had the effect of bringing together trades which before were scattered, and of supplying by machinery that which was formerly accomplished by manual skill and dexterity. This is the usual effect of a greatly increased demand, the conversion of trades and individual occupations into manufactures, and although the production of a book handsomely bound in cloth, with a figured or embossed cover, and gilt ornaments, and lettering, would seem to depend for its production more upon individual skill than upon large and complicated machinery, yet here, as in so many other cases, the manufacturer has, to a great extent, superseded the mechanic.

Nearly all the trades subsidiary to the production of a book have passed through similar mutations. The paper on which it is printed is no longer made by the slow and costly process of moulding or framing a sheet at a time, but is produced with wonderful rapidity by means of highly complex and ingenious machinery: the ink with which it is printed is made in vast quantities in factories specially devoted to that sole object: the boards which form its sides are a distinct object of manufacture; the cloth which covers it brings into play textile machinery, the most elaborate in the world: the printing press which works off the copies is specially adapted to the steam engine, which sets it in motion with admirable speed and precision. Had it not been for changes such as these, which belong almost to our own day, the thirst for knowledge, which now happily pervades all classes, could never have been allayed; education could not have diffused her blessings, and the best security for national peace and order would have been wanting. In all these cases, the machinery which has superseded hand labour in some directions has led to a vastly increased amount of hand labour and intelligence in other directions. There is now a greater demand than ever for type-founders and for compositors, for literary men and for artists; for engravers on wood and engravers on metal. And if in the binding of a book, the workshop has expanded into the factory, and if many of the manipulations of the binder are now superseded by machines, there are more folders, more sewers, nay, there are even more finishers than formerly existed; for the great demand for machine-bound books, so to speak, has led to a corresponding increase in the better descriptions of binding, which depend almost entirely on the taste and skill of the workman. The same principle is at work throughout the useful arts. A successful machine may supersede certain descriptions of hand labour, and cause for a time much privation and suffering, but it is sure to increase the demand for labour in other branches; a well ascertained fact which ought to be constantly borne in mind by the intelligent workman. He ought to seek every opportunity of acquiring skill in more than one department of his trade, so that should his services in one direction be superseded by a machine, he may be able to apply his skill in another.

The effect of machinery upon the literary man has been, and is, in many respects highly beneficial. It is gradually raising his occupation into a profession, entailing the necessity of solid acquirements, an accurate style and business-like habits. He no longer writes under the uncertain favour of a patron, whose smiles must be purchased by the sacrifice of independence: he has now no occasion to dress like a man of fashion, or take charity in the shape of a humiliating "list of subscribers" to his work. The public is his patron, and his publisher his best friend.

Machinery has also had a marked effect in raising compositors into a highly intelligent and respectable class. It has increased their numbers and improved their efforts. Men who are constantly engaged in perpetuating information and intelligence must to a great extent become informed and intelligent. The compositor, the reader or corrector of the press, must be constantly assimilating some, at least, of the intellectual food which they assist in preparing for the world. Their labour can never be superseded by machinery, although machinery may greatly increase its extent and importance, and just in proportion as they become skilful and intelligent do they become valuable to the literary man with whom they are so intimately connected.

When the author and the compositor have accomplished their respective duties, the one in supplying "copy," and the other in "setting it up" in type, the manufacturing processes of a book may be said to begin. For the sake of convenience and economy, books are printed in sheets, the sizes of which are named according to the number and size of the pages in each sheet. The largest size is termed folio, (Latin folium, a leaf or sheet of paper;) the next size is quarto; then follow octavo or 8vo; duodecimo or 12mo, 16mo, 18mo, 24mo, 32mo, &c., which contain on one form or side of the sheet 2, 4, 8, 12, 16, 18, 24 and 32 pages respectively; but as all the sheets are perfected, that is, printed on both sides, these numbers must be doubled to give the actual number of pages in each sheet. Each of these sizes also admits of many varieties: thus, an octavo, although always consisting of 16 pages, may be square octavo, royal octavo, super-royal octavo, &c., which leads to very great complication.

The arrangement of the pages of one side of a sheet or of a form in their proper order, and the wedging them up in an iron frame called a chase, preparatory to their being printed, is called imposing a sheet, and as the sheet is to be printed on both sides, there are two forms to be imposed for every sheet, an inner and an outer form; the outer form containing the first page of the sheet or of the book, and all the other pages which, when the sheet is folded, fall in their proper order with the inner form, which contains the second or left-hand page of the sheet, and all the other pages which, when the sheet has been folded and cut open, fall also in their proper order. The following diagrams will serve to illustrate some of the most important sizes of sheets,

in imposing the two forms of each sheet. It will be seen that by examining the folios or numbers of the pages of every two adjoining pages in a quarter, their sum makes one more than the number of pages in the whole sheet: thus in a folio 1 + 4 = 5 are imposed together; in a quarto 1 + 8 = 9; in an octavo 1 + 16 = 17; in a duodecimo 1 + 24; in sixteens 132, in eighteens 1 + 36, and so on in every other size; this combination continues through all the other adjoining pages, according to the order in which they lie in the chase to be printed.

As a complete book or volume consists of a number of sheets, properly folded and following each other in the order of the folios or pages, it is necessary to have some distinguishing mark to each sheet for the convenience of the printer, the folder, and the binder. The numbers of the pages would be too slow and tedious for the purpose; their chief use being for the sake of convenient reference on the part of the reader. The printer, therefore, inserts at the bottom of the first page of every sheet, what he calls the signature of the sheet,' and this usually consists of the letters of the alphabet, the first sheet being usually marked B, (A being reserved for the title, contents, &c., which are usually printed last,) the second sheet is marked c, and so on throughout the letters of the old Roman alphabet, which did not contain the letters JV and w: these are therefore omitted. When this alphabet is exhausted, the twenty-third sheet is signed AA or 2A, the twenty-fourth BB or 2B, and so on to the end. The third alphabet is written AAA or 3 A, and so on. It is also used for the purpose of guiding the printer in imposing and the folder in folding, to insert other minor signatures at the bottom of the third page of every sheet. Thus, if the signature of the first page of an octavo sheet be B, the signature at the bottom of the third page of the same sheet is B2, and in some cases the fifth and seventh pages are marked respectively, B3, B4. In some cases, especially in books printed in France and Germany, numbers instead of letters are used for the signatures. If the work be in two or more volumes, the number of the volume is added to each sheet, thus, VOL. II. B would be the signature of the first sheet of the second volume. In foreign books this signature would be simply 1 1. In both cases the number of the volume is inserted at the left hand bottom corner, and the letter or numeral near the right hand bottom corner.

In imposing a sheet of twelves or duodecimo, eight pages in each form are arranged together in the manner of a small octavo sheet. Above these eight pages, with a wider space between, four pages are ar

(1) This is sometimes improperly called the catch-word. The catch-word is the first word of every page after the first, inserted at the right-hand bottom corner of the preceding page, for the purpose as it was supposed of assisting a person in reading aloud, and insuring the correct turning over of the pages. It is seldom used in modern printing.

In folding the sheet, these four pages are first cut off, and the remaining eight folded like a sheet of octavo. The offcut is then folded down the middle twice, and inserted within the fold of the sixteen pages, thus forming altogether the required number twenty-four. In a sheet of this kind the signatures are carried to B 6, B 5 being the first page of the offcut, and however numerous the pages may be in a sheet with one signature, if they are all inserted, they are continued to the last odd page before the middle of the sheet, but they are never carried beyond the middle. In strictness it is not necessary to insert more than the first two to indicate the first fold of the paper, and the first of the offcut. The others only disfigure the pages, and are not of much use to the folder, who has only to keep the signatures on the outside, and the pages must be folded correctly. In French books the first page of the offcut is often indicated by some small mark printed at the bottom, such as..

No. 4 of the diagrams p. 153 is a sheet of twelves imposed with the first signature of the offcut in the inner form. By this arrangement it rises more conveniently for the folder, as it saves her the trouble of turning the offcut over every sheet. No. 5 is a sheet of sixteens to fold without cutting.

The sheets are delivered by the printer to the binder 2 in one of two arrangements. Suppose an edition of 1,000 copies of an 8vo work is to bound; the printer either delivers at once 1,000 copies of signature A, 1,000 of B, and so on to the end, or he causes them to be previously gathered into quires; that is, a single sheet of z, supposing that to be the last sheet in the book, is taken, and upon this is placed a single sheet of Y; on this is placed a single sheet of x, and by proceeding in this way in a retrograde order, the gatherer at length arrives at B, the sheets being all in the proper order for folding. He then takes the title, contents &c., (signature a) and folding all the sheets together into a quire, lays them aside and proceeds to make up or gather a second quire, and so on till the whole 1,000 copies have been gathered.

The folding is performed at the binder's by females educated for the purpose. They are seated before a long flat board or bench, and each folder, placing the open quire of sheets before her, and with a foldingstick or paper-knife in her hand, folds the sheet in such a way that one page shall be exactly opposite to another in each sheet, taking care that the signatures shall fall properly. The folding is accomplished with remarkable precision and despatch, the result of long practice. A good folder will fold 500 octavo sheets per hour, but the usual average is about 300. In folding twelves with an offcut, the time occupied in folding is usually doubled.

(2) In preparing this notice of bookbinding, the Editor wishes to express his obligations to Messrs. Remnant, Edmonds & Remnant, of Lovell's Court, Paternoster Row, for allowing theit processes and machinery to be inspected and copied. In this large and well-ordered establishment, 30,000 volumes per week are frequently done up in cloth, or bound in leather.