skill and experience. I am inclined, how- | heap is made, we have, in fact, exactly the ever, to believe that the opinion is to a conditions to occasion loss of its valuable certain extent correct. Supposing, then, constituents. It is exposed to a more or that two samples of such manure differ, it less free current of air, which facilitates the must be obvious that it is the dung and volatilisation of the ammonia as it is urine of the cattle which differ; the litter formed and it is exposed to the falling rain, mixed with such dung will be the same in which washes out the soluble salts, and both cases. Now, some experiments made what ammonia the winds have spared, into in the laboratory, on the pure dung and the subjacent soil. lt is true that the urine of cattle fed on Turnips and oilcake, former of these sources of loss can be got appeared to me to confirm the opinion of the better of by the use of acids or of the greater abundance of nitrogen in the gypsum and mixing with earth; but when produce of animals fed with the latter food. the ammonia is thus fixed, as it is said, it It will not do, however, to draw conclu- is fixed only as regards volatility, for it is sions in such cases from a single analysis, still soluble, and liable to be washed away so that I was anxious to have repeated and by rain. In order to have farm-yard dung extended the experiments, but circustances in the best state, it must be preserved under not within my own control have hitherto cover, and my impression is that the introprevented my doing so. I would beg you, duction of covered dung-pits is likely to however, to observe that supposing it to be prove of great importance. There seems made out distinctly that farm-yard manure to me no doubt that in this way manure, produced by oil-cake contains more ni- in whatever way produced, must be best trogen than that from Turnips, still this preserved. There appears, indeed, to be would not embrace the whole question. It but one objection, which is, the expense of would if you were to buy the manure, when, erecting a roof of sufficient extent to cover of course, all that you want is to get as the whole manure of a farm. But surely, much nitrogen as possible in the 100 tons, in these days of cheap building, some sort or any other quantity which you may wish of inexpensive cover may be contrived. In to buy. But it is quite another thing when order to ascertain this, we should have to you come to produce the manure on your ascertain, by actual experiment, what is the own farm. The question then is, not amount of gain by having the manure kept whether 100 tons of the one contain more under cover, so as to know whether it is nitrogen than 100 tons of the other; but sufficient to leave a profit on the expense whether the whole quantity of nitrogen of covering it. We have another matter to produced by the one method of feeding is attend to also, in the management of farmgreater than the whole quantity of it pro- vard manure-its fermentation namely, by duced by the other. Now, we have no which is meant the production of such a experimental information on this point; decomposition as converts the nitrogen prebut I think it may be doubted whether in sent into ammonia. The importance of this this point of view there is any such dif- decomposition depends upon the fact that ference, because you will observe that by this means we obtain a manure which though oil-cake contains more nitrogen-acts with greater rapidity than one in which in fact about 24 times as much as Turnipsstill there is a much greater disproportion in the quantities of these substances with which you supply the cattle. You give an ox daily 1 cwt. of Turnips, but no one gives 30 lbs. of oil-cake daily, but more nearly 3 lbs. ; so that, in fact, the ox fed on oilcake actually on the whole receives less nitrogen than when fed on Turnips. To pass then to another question-supposing cattle to be fed in exactly the same way, so as in I have referred hitherto solely to natural fact to produce manure which at the mo- manures, and have laid before you my view ment of formation is of uniform quality, that no artificial manure will ever prove a what are the circumstances under which substitute for that of the farm-yard; but that manure can be preserved with the least though that is the case, they may be, and loss of its valuable matter? As regards I believe are, most important auxiliaries. the general question of the preservation of Take the commonest kind of artificial mamanure, I apprehend that the most impor-nure-I mean, of course, guano-the finest tant matter is its protection from air and quality of which is the cheapest and the moisture. In the way a common dung- best of the class. I say the cheapest and this decomposition has not been effected. The fact is, that the formation of ammonia takes place much more slowly when it has been incorporated with the soil than when it is heaped up in the dung-heap; and, as the nitrogen must pass into the state of ammonia before it is absorbed by the plant, we require to effect as much of that change as possible, if we are to have a manure of rapid action. the best; and it must necessarily be so, because the constituents which are of greatest value to the agriculturist, are given in it in a larger quantity than in any other compound for the same money. My advice then is to buy the best guano-never purchase inferior. The inferior is greatly more expensive. The decrease in the money value for which it might be obtained is nothing to the decrease in its valuable constituents as compared with the better sorts. The Peruvian is the best kind of guano, and it is by far the cheapest. Farmers are exposed to much risk of imposition in this matter; adulteration is carried on to an extent which it is difficult to credit. I have recently gone over the number of samples of guano that had been forwarded to the office of the society for analysis, to the number of 30 cases, and have found that of that 30 there have been only 9 samples of such a quality as I, if purchasing, would have been disposed to accept. And this gives no accurate idea of the proportion of good to bad guano which is in use. Numerous samples of good guano have come to the office, but few of those that are thoroughly adulterated, because the venders of such take care to keep as far as possible out of the reach of the chemist. Take guano of the best quality and you will find that two things enter largely into its composition, viz., ammonia and phosphoric acid, the two substances, as I have previously stated, the presence of which is most valuable in farm-yard manure. Now, in peruvian guano you will find about 17 per cent. of ammonia and of phosphate of lime, a compound of lime and phosphoric acid, 23, 24, or 25 per cent., according to oircumstances. In inferior guanos there may be found 23 or 24 per cent. of phosphate of lime, and 1 or 2 of ammonia; and this, instead of being sold at one-third of the price of the other, as it should be, is sold generally at two-thirds. Guano may be considered as the type of a class of manures, and bones may be taken as belonging to it also. The value of that kind of manure is dependent on two conditions. Some use burned bones. Now, in certain circumstances, this may be advantageous. The addition of phosphate of lime alone may be needed in certain soils. Such a case occurs in the pasture land of Cheshire. The application of bones to that exhausted soil operates almost as a charm upon it. The peculiar nature of the tillage under which it has been kept-all the butter and cheese raised upon it being conveyed elsewhere-reduces it to that state that the addition of phosphate of lime acts powerfully, and is indeed eminently beneficial. But, in general, such is not the case, and therefore they should give the preference to bones that were unburned. There is another instance of a similar kind to which I may refer. In many cases, I believe, bones are sold from which the glue has been extracted by boiling. This glue is a valuable commercial product. It is used in weaving, for stiffening yarn and other manufacturing purposes; and several manufactures have large boilers in which the glue is extracted. The bones are sold afterwards at no diminution of price from that of unboiled bones. ON THE SOLIDIFICATION OF MORTAR AND ITS PROPERTY OF RESISTING THE ACTION OF WATER. BY M. H. DE VILLENEUVE. M. VICAT, in his researches into the action of cements, has pointed out the principal properties of different kinds of mortar, including that known as hydraulic mortar. The power of resisting the influence of water is communicated to lime by a certain combination of silica and alumina; this combination may be formed in two different ways, that is to say, either directly, by calcining calcareous clays, or indirectly and gradually, by the action of burnt marl or clay on lime. The calcination of carbonate of lime, containing from 1 to 6 per cent. of clay, produces ordinary lime; if the quantity of clay be greater (equal to from 6 to 23 per cent.) the lime is suitable to be made into hydraulic mortar. With from 23 to 27 per cent. of clay, the result of the calcination of the calcareous compound is termed cement. Marls and clays, subjected to a proper degree of heat, produce what is called pozzolana, which is more or less energetic, according to the purity of the clay from which it is obtained. Practical experience has shewn that, between the lime suitable for hydraulic purposes and cements, a line of demarcation exists, in the form of the lime, containing about 23 to 28 per cent. of clay. This combination neither slakes into a grey powder when wetted with water, nor does it cohere permanently when mixed with water and beaten together. When calcined calcareous compounds are moistened with water they experience an augmentation of volume, owing to the solidification of a portion of water in combination with them, and the lime breaks down into a powder. The com 1 1 1 1 2 སྙ : obtained capable of persistent cohesion. These considerations laed to the belief that the hydraulic property of some kinds of lime is attributable, not only to the presence of silica and alumina, but to that of carbonic acid, or, indeed, any other electronegative substance, capable of forming an insoluble compound with lime. Insolubility must, then, be regarded as the essential peculiarity of hydraulic lime. Carbonic acid renders lime hydraulic, not only by di indirect action, as in pozzolana; thus cement and hydraulic lime which, by long exposure to the air, have become charged with carbonic acid, may be mixed with ordinary quick lime, and may then be used instead of the best pozzolana. By pounding hydraulic mortar after it has stood for four years, a true pozzolana was produced, which became quite fixed under water, in the space of fourteen hours. As a hydraulic principle, carbonic acid is the most economical; but it does not produce the most cohesive mortars and cements. bination with water takes place with a violence, rapidity, and heat, proportionate to the smallness of the quantity of clay; the proportion of water absorbed also depends on that circumstance. When water is made to act on ordinary calcareous substances after calcination, the absorption of the water, and the breaking down of the lime, will not take place when it is of the kind containing 23 to 27 per cent. of clay but the mass will only be divided into lumps. It has been found that, when lime contain-rectly combining with it, but also by the ing only from 23 to 28 per cent. of clay, and cements, are submitted to the action of water at a high temperature, even if steam only be employed to moisten the lime, it will swell up and then fall to powder in the same manner as hydraulic lime, and the properties of the calcareous matter, slaked in the manner above mentioned, are equal to those of hydraulic lime of the best kind. If, on the other hand, instead of favoring the action of the water, it be impeded, either by keeping down the temperature, or by adding it only in small successive portions, the swelling up of the mixture, A calcination or moderate roasting, proand the formation of that noxious combi- duces a modification in calcareous clays, by nation of clay and lime, in which the former which they are brought to a state very is in the proportion of 23 to 28 per cent. of similar to that of lime containing 23 to 28 the latter, can be checked at pleasure. This per cent. of clay. The hydratation of these peculiar kind of lime, if submitted to the substances, increased by heat, or impeded slow action of water, or even to the hygro- by a low temperature and a limited supmetric action of the atmosphere, and after-ply of water, gives rise to two classes of wards pounded up, will produce an excel- products, namely hydraulic lime and celent cement. By submitting the argilliferous ment. These latter products are, moreover, lime to the action of water, under certain endowed with a remarkable degree of coheconditions, it is capable of being used in- sion; indeed, cement has been produced by stead of hydraulic lime of the best quality; this process capable of scratching the surand, by treating the same kind of lime face of marble. The most remarkable rewith small quantities of water at a low sults of this kind are, however, obtained temperature, and afterwards grinding the from calcareous clays, rich in alumina; mass as above described, a valuable ma- these are the compounds which experience terial for cement is obtained. Certain the highest degree of contraction in the carbonates of lime, sometimes termed sub-process of calcination. From what has carbonates, give rise to a product similar to the argilliferous lime; and, if slightly moistened and ground, it produces durable cement, which can be employed alone, or mixed with ordinary hydraulic lime. If the action of the water on the subcarbonates be assisted by heat, it falls into powder in the same manner as common lime. If the temperature be raised, the substance is acted on like a mixture of lime and the neutral carbonate of lime,-a phenomenon similar to the decomposition which is observed when hydraulic lime is acted on by a large quantity of hot water. By causing water to act slowly upon the imperfect carbonate of lime, or rather by exposing it to the hygrometric influence of the air, and afterwards grinding the mass, a substance is been said, it appears that the various products of the calcination of calcareous compounds have each a certain utility, and that all of them may be profitably employed either before or after being burnt. Practically, it is evident that hydraulic lime may be obtained economically in all localities where beds of chalk or limestone are found, and that the various products of the unequal calcination effected in ordinary kilus may be turned to advantage. The system above detailed has been tried for fifteen years in some parts of France. 350,000 cubic yards of masonry, in the railway from Marseilles to Avignon, prove at the present moment the advantages of the system; in the neighbourhood of Marseilles, there are upwards of a million cubic yards of masonry, constructed with hydraulic mortar, (made as above described) at a price not exceeding that of work executed with mortar made from ordinary lime. ABSTRACTS OF SPECIFICATIONS OF Improvements in the Manufacture of Fuel In the manufacture of "manure," the patentee employs highly-carbonized refuse tan and night-soil in equal parts. The prepared tan acts as a disinfector, both in the case of its use with night-soil' and in other applications thereof. The patentee does not claim the exclusive use of tan or peat for fuel, as he is aware that they have been previously employed in combination with other materials, but he considers the application of tan and peat, combined with tar or resin, or resin oil, as above described, to be new; without, however, confining himself to the exact proportions above given. Claims.-1. The application of highlycarbonized refuse tan and night-soil for the purpose of manure. 2. The employment of the tan charcoal for the purpose of disinfecting and deodorizing night-soil and other materials. Certain Improvements in the treatment of These improvements apply principally to the smelting of refractory copper ores, and consist in the employment of a flux composed of Galena (sulphuret of lead) and baryta, or sulphate or carbonate of baryta. *Collected from The Mechanic's Magazine. In place of baryta, carbonate or sulphate of strontia may be substituted. The proportions are one-tenth galena and nine-tenths baryta, &c. The flux is to be added to the metal in the roasting furnace in the proportion of one-eighth flux to seven-eighths of ore yielding 12 per cent. of copper. Another improvement is the employment of oxygen gas, to increase the heat and cause more perfect combustion of the coal. Retorts are fixed near the furnaces, in which the gas is generated by exposing therein black oxide of manganese to intense heat. The gas evolved passes to a receiver, and thence by pipes to the fire, either through holes cut in the side or over the bridge of the furnace. The patentee also employs carbonate of baryta as a flux for iron ore, and introduces oxygen gas to assist combustion, as above described. Claims.-1. The employment of galena, or sulphuret of lead, in combination with baryta, or carbonate or sulphate of baryta, or carbonate or sulphate of strontia, as a flux for copper ores, as described. Also the generation and application of oxygen gas for increasing heat in smelting and roasting furnaces, as described. 2. The employment of carbonate of baryta as a flux for iron ore. Also the application of oxygen gas, as described. Improvements in treating Peat and other carbonaceous and liquid matters so as to obtain products therefrom. WILLIAM BENSON STONES, Golden Square, Middlesex, Manchester warehouseman. (A communication.) Patent dated March 7, 1850. Claims.-1. A machine for compressing peat. 2. A process of carbonizing. 3. The application of carbonic acid gas to the extinction of glowing char-peat. 4. The employment of peat-gas produced during the operation of carbonizing, for the purpose of heating the retorts. 5. The application of a series of receivers to the distillation of the residuum, and the obtaining products therefrom. 6. A process of obtaining "peotole" and "peupion" by rectification. 7. A process of obtaining "peotine." 8. The application of sulphur and peat to the manufacture of bisulphuret of carbon, and application of the peat and sulphur residuum to the manufacture of gunpowder. 9. The manufacture of artificial fuel from anthracite and char-peat. 10. The impregnation of surface peat with resin-oil, &c., for the manufacture of) air, when a coil or plate of platinum is fire-lighters and revivers. 11. The purification of peat gas, as described. 12. The obtaining of heat and light by the combustion of peat gas in atmospheric employed. 13. A peculiar construction of gas-burner, and application of these burners for the purpose of blow-pipes, &c. III. PHARMACY, MATERIA MEDICA, THERAPEUTICS, &c. that their darling hopes and interests must have fallen with it. Thanks to their sagacity, they have judged correctly. But, shrewd and designing as they are, their ambition and their cupidity will beat them at last, for the Society is fast progressing towards dissolution under the unquenchable thirst of those leeches who have fastened upon its vitals. THE PHARMACEUTICAL SOCIETY. LAST month we announced that Mr. Jacob Bell's name was to be omitted from the title page of his Journal. We made this statement upon the assumption that he would carry out the recommendation to that effect of a committee appointed by the Council to consider the subject of the Memorial. He has set the Council and their committee at It could be clearly shown that a subscripdefiance by not adopting their recommend- tion of five shillings a year from each of ation. We admire him for his courage in the members would be amply sufficient to not blinking the matter at issue by such a maintain in efficiency all the legitimate ridiculous compromise; for the real ques-objects and functions of the Society. Of tion is, whether or not he shall enjoy the monopoly of supplying the whole of the members and associates of the Society with his Journal. course those monstrous absurdities, the genteel pauper school and its monopolising propagandist coadjutor, the Journal, must go to the wall under such a depleting system. The monthly meetings, the examination board, the library and the laboratory for the use of the members only, and the publication of the Society's transactions, could flourish upon such a revenue, as, though small the amount of each individual's contribution, it would be large in the aggregate, from the greater number of chemists who would join and support the The Journal is solely the property of Mr. Bell; he alone is responsible for its contents. Therefore, whatever credit or blame belongs thereto, he has rightly determined to bear on his own avowed responsibility. We have strong reasons to suspect that those who advocate this compromise are desirous to get the Journal into their own hands to further their own selfish schemes. Such a change, to the members, would be only for | Society under this desirable arrangement. the worse. Whatever Mr. Bell's objects may be in fighting for the monopoly, he is well known to be a more generous and disinterested man when placed in power than his compromising colleagues would be were they in his position. Their jealousy of him would have caused them to have crushed his monopoly long since, had they not feared These necessary reforms will never be accomplished unless the management of the Society passes into other hands, because those on the Council who have energy are opposed to them from interest, and those who are not so fettered have neither the spirit nor the ability to originate and develope such an organic change. |