s formed by the partial decay of vegetable matter, especially of various species of mosses. It exists in most parts of Northern Europe. The vast peat-bogs of Ireland, amounting probably to not less than three million English acres, of an average depth of 19 ft, represent an amount of raw material which is now being looked to by economists as a source of wealth, instead of being the exponent of sterility. Peat may be made valuable in various ways; first, as a source of fuel. At present, however, while coal is abundant and cheap, peat will probably be unable to compete with it. The time may come when the country will look with eagerness to Ireland for the supply of fuel, which is a necessary element in our greatness and prosperity; and that time may not be so far distant as is generally supposed, when we consider the fact that our present annual consumption of coal is about seventy million tons. In the year 1856 the quantity of coal raised in the United Kingdom amounted to 66,645,450 tons.

In the article FUEL, some details are given respecting peat as a source of heat, and we may here give a few additional particulars. The heating power depending on the per-cent-age of pure carbon found in the peat, the source of the supply becomes a matter of importance, seeing how very variable is the value of the peat in different localities. Dr Sullivan states that "the variation in the quality of peat is so great, that no statements as to its economical value can be relied on which do not give the per-cent-age of ash, the per-cent-age of water, and the specific gravity. The variation in the latter amounts to 0·3 to 1·1 for air-dried turf from the great centre bogs." Mr W. Longmaid states that "the best samples of peat contained, when dried, about 70 to 75 per cent. of carbon; but other samples were contaminated with earthy matters to the extent of from 5 to 10 per cent.; the average impurities may be taken at from 4 to 5 per cent., and we have found some samples of peat charcoal yielding 94 per cent. of fuel."

Messrs Gwynne & Co. have taken out several patents for the preparation of peat fuel. In one of their patent processes, the peat, as dug from the bog, is deprived of much of its moisture by being placed in a large centrifugal machine, after which it is ground to powder, and passed through a series of cylinders revolving in a heated chamber, where the remaining moisture is got rid of, and the powder raised to the proper temperature for compression; it is carried from the last cylinder by two pockets to the compressing tables, and having passed through them, the solidified peat is ready for use. In another process the moisture is got rid of by passing the peat between cylinders containing, at equal distances along their outer surfaces, projections equal to the thickness of the slabs of peat. The drying of these is completed in the hot chamber, or they are at once converted into charcoal. It is found that when the peat powder has been dried at a temperature of about 180°, and in that state allowed to enter the hopper of the compressing engine, the tarry properties of the turf are just sufficiently developed to form a good cementing compound, and the brick of compressed turf, when cold, forms a dense and very pure fuel. Dr Letheby, who has examined this patent solidified peat fuel, reports that its specific gravity is as high as 1·140, its structure hard and dense, and the stowage weight of one cubic foot of the fuel is 71·24 lbs, that of Newcastle coal being about 49-69 lb. 100 parts of the peat contain 9 of hygroscopic moisture; they yield 55 parts of volatile matter, much of which is condensable, and 36 of charcoal. The charcoal contains 3-8 of ash. 7000 grains of the peat were distilled in an iron retort, and the volatile products were conducted through a red-hot iron tube, under the impression that the paraffin, &c., of the tar would be converted into a gaseous hydrocarbon of high illuminating power. The results were 2520 grams of peat coke, or charcoal; 1320 of ammoniacal liquor; 360 of thick tar; and 2800 of combustible gas; the gas occupied 625 cubic feet, and when burnt at the rate of 5 cubic feet an hour, from an Argand burner, with 15 holes, and a 7-inch chimney, it yielded a light equal to that of 7 sperm candles, each burning at the rate of 120 grams per hour. According to this analysis, 100 parts of the peat furnish

| Porous charcoal | 36-00 | |----------------|-------| | Ammoniacal liquor | 18-86 | | Thick tar, containing paraffin | 5-14 | | Gas having the illuminating power of 7 candles | 40-00 |

Although the illuminating power of the gas is not very high, the quantity is considerable (a ton of the material furnishing as much as 14,000 cubic feet), and as much of the gas and paraffin had been rendered gaseous by their passage through a red-hot tube, they might probably be further decomposed and converted into gases of high illuminating power. When the gas had been purified, by passing it through an alkaline mixture, it was found to be free from sulphur, in which respect it has an advantage over coals.

In using the solidified peat as fuel, no opaque smoke is evolved, no sulphurous acid is set free, the heat is quickly raised and quickly diffused, the ashes do not form clinkers, and the peat does not contain any metallic sulphurite, or other substance that is likely to produce spontaneous combustion.

Messrs Gwynne propose to apply their prepared peat to the reduction of ores by combining it with the proper fluxes; and having formed the furnace charge of fuel, flux, and ore, by powerful compression into globular masses, these are piled up in the furnace, the spaces between them admitting a sufficient quantity of air for maintaining the combustion. Peat charcoal is of great value in the manufacture of iron, on account of its being almost free from sulphur. Its deodorizing and purifying qualities are also high.

According to Mallet (whose experiments on Irish peat have been generally confirmed by those of Brix on Prussian peat), the heating power of good dry turf, as compared with that of the coke of bituminous coal of good quality, is as 1 : 7-61, and air-dried peat will convert about its own weight of water, at 60°, into steam at 212°. In Bavaria peat is dried artificially to a large extent as fuel, for the use of locomotive engines; and at Konigsbrunn it has for many years been employed in the puddling furnaces for the conversion of cast into wrought iron.

Peat has thus been shown to be valuable, first, as a fuel; secondly, as a source of illuminating gas; and we have now to refer to it in the third place, as a source of various products obtained from its destructive distillation. The ultimate elements of peat are essentially the same as those of wood and of coal, namely,—carbon, nitrogen, hydrogen, and oxygen. If, therefore, peat be distilled in close vessels, the resulting products will resemble those of a similar operation on wood or coal. In the Great Exhibition of 1851, Mr Oxlaid exhibited the products obtained by the destructive distillation of Dartmoor peat in cast iron retorts; but as the expense of the process was too great for its adoption in Ireland, it occurred to Mr Reece to make use of a blast-furnace similar to that employed in the smelting of iron ore, with an additional contrivance for collecting the products of combustion. By this means peat has been made to yield ammonia, acetic acid, pyroxylic spirit, tar, naphtha, oils, and paraffin, all useful products in the arts. The ammonia which is fixed and separated by the addition of sulphuric acid, forming sulphate of ammonia, is employed in the preparation of carbonate and hydrochlorate of ammonia, of caustic ammonia, and in the production of manures and composts. The acetic acid, which is fixed and separated by the addition of lime, forming acetate of lime, is a useful source of acetic acid, and of various acetates consumed by the calico-printer. Pyroxylic spirit, or wood alcohol, may be separated by distillation, and is used in vapour-lamps, and in the preparation of varnishes. Naphtha is also used in making varnishes, and for dissolving caoutchouc. The heavy and more fixed oils may be used as cheap lamp oils, and for making lamp-black, or, mixed with other unctuous substances, they are well fitted for the lubrication of machinery. Paraffin, either alone or mixed with sperm or stearine, forms excellent candles. Paraffin is a crystalline substance of the specific gravity 0-870. It is destitute of taste, colour, and odour; at 112° it is a transparent oily liquid, and at a higher temperature it boils and distills without change; its vapour burns with a white sootless flame. It resists the action of acids, alkalies, chlorine, and potassium, and cannot be united by fusion with camphor, naphthaline, benzole, or pitch. It is on account of this inertness as a chemical agent, or want of affinity, that it derives its name from parum affinis. It unites, however, with stearine, ceteine, bees-wax, and colophony, and dissolves in oil of turpentine and in naphtha. Mr Bagot states, that 100 tons of peat yield 10,000 gallons of liquor containing ammonia, carbonic acid, acetic, and pyroligneous acids, pyroxylic spirit, and 1000 gallons of tar, containing paraffin, heavy oil and light oil. The inflammable gas is economically used by being passed under the steam-boiler. The 1000 gallons of liquor yield one ton of sulphate of ammonia, sufficient acetic acid to produce 13 cwt. of grey acetate of lime, and 52 gallons of pyroxylic spirit. The tar yields 300 lbs. of paraffin, 200 gallons of naphtha, or light hydrocarbaceous oil, and 100 gallons of heavy oils.

The above results are, however, much too favourable for constant practice. Dr Sullivan has ascertained that none of the paraffines of commerce are definite bodies; but mixtures of different isomeric hydrocarbons. In relation to the distillation of peat, he says:—“Now that a ready market exists, I have no doubt that 3 lbs. of paraffin per ton of good dry peat could be separated, especially by keeping over the summer oils until winter; in cold winters, perhaps even more. Gas enough can be produced to work the factory (heating stills, &c.), but it has now been satisfactorily determined that the larger the supply of gas, the less will be the yield of tar, and vice versa.” The yield of tar when the temperature has been carefully attended to, has fully reached the anticipated quantity; but neither the ammonia nor the wood spirit has. The real source of profit, therefore, is the tar. “Tar about 3-5 per cent., paraffin 0-13 per cent.” (Private communication.)

Thus it will be seen that whether we regard peat as a fuel, as a source of charcoal, of gas, or of the various other products named, it cannot, except for the sake of the tar, be worked at a profit, until the manufactures connected with it can compete in price with similar products already in the market. It must, however, be remembered, with respect to peat as a source of fuel, that while coal would cost the Irish labourer three times as much as it costs the Northumbrian cottager; the peat is at hand, and can be had almost for nothing.

(c.t.)