suspend this tendency. Another example of the facility with which wool felts, is the common flock mattress, which is made of carded wool sewn up in ticking the warmth and slight motion which it gets by being slept upon are sufficient to cause the fibres to accumulate round certain points, whence result those knobs and lumps of imperfect felt which render it necessary after a time to empty the bag and recard its contents. "A piece of woollen cloth that has undergone no process after that of weaving, may without difficulty be unravelled; but after it has passed through the fulling mill it is no longer subject to this action, the filaments of which each adjacent thread is composed being entangled together by a species of felting. The result of this is that the cloth shrinks in length and breadth, but becomes proportionally thicker and more dense. The higher the heat is to which the cloth is exposed, and the longer it is continued, the more compact does the felting become; on which account it is that the modern practice of giving a gloss to woollen cloths by rolling them up very tight and then boiling or steaming them for some hours, gives them a compactness and leathery consistence in which all the advantages both of felt and of woven cloth appear to be united. "But the mere structure of wool and of hair, as I have now described it, is not of itself sufficient to account for the formation of felt on the contrary, it might be expected that the filaments being, when put in motion, free to move only in one direction, should continually diverge more and more from one another. This would actually happen in an attempt to make dense felt of unprepared hair of any kind, because all hairs are straight, or rather have only one gentle curve from point to root, and likewise possess a considerable degree of stiffness or elasticity. The fibre of wool, on the contrary, is naturally crinkled or of a zig-zag figure, which it retains with great pertinacity; for if drawn out till straight it immediately contracts again to its former figure on being let go. Now this figure, besides opposing a great resistance to the progressive motion of the filament, must have a continual tendency to change the direction of such motion. The result of this would be the formation of a ball if the pressure were equal on all sides, or a plate or layer if the chief pressure were only in two opposite directions." A word of economical import concerning 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 beaver 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 substitution of silk or hemp as the material of the body of the hat. We may therefore distinguish five kinds of hat: the beaver hat, of which the body is felt and the nap of beaver; 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." The paper which has chiefly interested us is that on Bone, and from it we take our remaining extracts. It furnishes striking illustrations of the philosophical truth that there is no substance which science cannot turn to profitable account; even articles which people in their ignorance regard as nuisances or utterly worthless for any practical purpose, are often valuable, and may be made the source of beautiful and precious productions. Nay, although bones have always been used as one of the ingredients of a dunghill, it has only of late years been ascertained that they possess extraordinary value as manure. We quote an anecdote here: "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. He invented or got made for him, a machine for crushing the bones; and then spread them as a topdressing 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 contributed much to this striking amelioration; but the earth of the bones, especially the phosphate of lime, also bore its share in it." With regard to the chemical qualities of bone we thus read: "Decomposition in close vessels of the single substance, bone, produces five new substances; namely animal charcoal, carbonate of ammonia, animal oil, water, and an inflammable gas. A low red heat volatilises 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 compounds. The water, the carbonate of ammonia, and part of the oil are condensed 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 separated 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 pro cesses 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 call 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 as the basis of black pigments, ivory-black having been first so applied by the celebrated Greek painter Apelles. "Some years ago, a German chemist of the name of Lowitz settled at Petersburg, 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 vegetable and animal substances in a state of spontaneous decomposition. This interesting 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 decolouring 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." But even delicate and highly nutritious food may be obtained from bones; for they are charged with vital matter: : "With regard to bone itself, there is no doubt that it is as truly organised and vital as any other part of the body. As soon as the rudiments of a young animal can be distinguished before its birth, the place of the future. bone is indicated by a soft or semi-fluid matter inclosed in a delicate membrane by degrees both the membrane and the matter which it incloses become more dense and cartilaginous; opaque white spots then appear which soon after are penetrated by vessels carrying red blood: the deposition of bone then begins and at the same time the cartilage seems to be gradually replaced by membrane. The rudimental bone which at first was solid, now begins, at least in the long bones, to exhibit an internal cavity or hollow axis; thus showing that, while fresh matter is continually depositing to supply the growth of the bone, that which had been already deposited is removed, and that this latter process takes place in the interior of the bone at a greater rate than the other does. The activity of the two vital processes of deposition and removal, or, to speak in technical language, of secretion and absorption, is of course proportioned to the rapidity of growth; so that during the early periods of life the bones participate with the soft parts of the body in the continual change and flux that is taking place within them. When the full stature of the animal is attained these two actions probably diminish in rapidity, but still are kept up sufficiently to preserve the life of the part. As old age approaches, the removal of the earthy ingredient of bone seems to become more difficult; its proportion therefore to the membranous ingredient increases, and hence the bones of old animals are harder, of greater specific gravity, and more brittle than those of younger ones." All animals that eat flesh will eat bones, and they spontaneously decompose much more slowly than the soft parts of organised creatures do. Bearing these things in mind our concluding extracts will be read with additional interest : "When very hard pressed indeed he can stave off famine for a while, as Captain Franklin and his party did more than once in their exploratory arctic expedition, by taking bones which even the wolves had left, and scorching them so as in some degree to subdue their hardness and thus render it possible to gnaw and masticate them as a succedaneum for food, or, at least, as some alleviation of the agonies of famine. "But the animal matter of bones is best extracted by hot water. Every housekeeper knows that the nutritive quality of meat soups is much increased by boiling the bones together with the meat. In this way however only a small proportion of the food contained in the bones is made available; for part of the gelatine is with difficulty, and the membranous part is not at all soluble in common boiling water: much even of the fat is locked up in cells of the bone from which it cannot escape except these cells are broken into. "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 extremities 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 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 animals, the gelatine seems to be in a state of condensation 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 absorption of the water, without however becoming viscid. A second boiling for three or four hours in fresh water dissolved out a considerable proportion of 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° its boiling point in the open air, to 270° or 280°. At a less heat than even the former of these not only the condensed 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 headquarters in France, and memoirs have been published 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 susceptible of decomposition or of destruction by rats or mice, and which would require no other magazine than simply making them into stacks and covering them with a roof of thatch or any other material." Again : "The scrapings, shavings, or sawdust of bone is an article that bears a good price in the market, being much used by pastrycooks 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." Throw not therefore an old dry bone away from you: it will at least make excellent manure, if not handles, and perhaps good soup or jelly. ART. V.-1. Eleven Years' Residence in the Family of Murat, King of POOR humanity! And how nearly equal are all men! Peasant and prince are in many ways on a perfect level. Not only do disease and death dispose of them alike, but fickle fortune tosses them backwards and forwards as if with a most wanton hand. What, although a king of Naples was of meanest origin, or Louis Philippe of royal blood, the former could act the monarch well, while the other was an exile, a wanderer with his scantily provided wallet upon his shoulder, and uncertain where to find a resting place, or how to appease the cravings of hunger? Yet the days were to come when their conditions were again to be quite reversed, |
