Bildersaal deutscher Geschichte

Bär, Adolf; Quensel, Paul

Bibliografische Daten

Monografie

Persistenter Identifier:: 1646837127308

Titel:: Bildersaal deutscher Geschichte

Untertitel:: zwei Jahrtausende deutschen Lebens in Bild und Wort

Autor:: Quensel, Paul

Herausgeber:: Bär, Adolf

Verleger/Verlag:: Union Deutsche Verlagsgesellschaft

Erscheinungsort:: Berlin

Erscheinungsjahr:: 1902

Umfang:: XII, 400 Seiten, 48 Tafeln

Sprache:: deutsch

Strukturtyp:: Monografie

Standort:: Bibliothek des Historischen Instituts, Universität Stuttgart

Signatur:: Ae 95 sekr

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

Kapitel

Titel:: Deutsches Volksleben im Mittelalter

Strukturtyp:: Kapitel

Kapitel

Titel:: Aus der Zeit des ersten Bücherdrucks

Strukturtyp:: Kapitel

an} THE CHEMICAL NEWS. On Manure Phosphates. 37 * If this produ is made without a surplus of lime, and dried at a temperature not exceeding 100° C. (=212° F.), it is found, after long experience, to have the same effe® on soils which do not contain too little humus, This pro- perty has hitherto been recognised by few chemists. However, the time will come when these phosphates will Ye judged according to their value. In a well manufagured produé of that kind, go togy per cent of the contained phosphoric acid are soluble in the oxalate, and of those again 25 to 35 per cent in the citrate of ammonia. If, however, this precipitated phosphate is made with a surplus of lime, or dried at too high a tem- perature, it loses its property of being assimilated by the s0il as quickly as superphosphate, and becomes as soluble in citrate as in oxalate. Next there belongs to this second class the phosphate in ‘he different guanos which contains 50 to 85 per cent of their phosphoric acid soluble in the oxalate.. The phos- shoric acid in the guano, though only very slightly soluble n the citrate, and in water only in traces, always was considered as highly assimilable. To treat the guano with sulphuric acid, as it became -the fashion on the Continent some years ago, is merely done to fix the immonia. Further on we have to put in this category the phosphate of the raw bones and of the black-burnt bones, the latter seing in rather large quantities on the Continental mar. cets, They contain 45 to 70 per cent of their phosphoric acid soluble in the oxalate. That the phosphoric acid in :he two latter named states, of being speedily assimilated n the soil, is known to every farmer. It is not said, how- iver, that they would not profit by being treated with sul- shuric acid and converted into bone superphosphate. Then follow some mineral phosphates, in which 30 to 30 per cent of their phosphoric acid is soluble in the >xalates—as some phosphates of the French Ardennes, .n the neighbourhood of Rheims, Dun, Verdun, some shosphates of Cahors, St. Antoine, St. Jean de Laur, Cher, and Lot. All those phosphates are used with excellent 2ffed, only finely ground, for manuring purposes, not only 'n the neighbourhood of the places named, but even at considerable distances. This proves that their employ- ment was always crowned with decided success; for fresh- hrocken woodland, turfy ground and soils rich in humic acids, they exercise an excellent effet, even better than superphosphate could do. in this category is also to be named a phosphate which s found near Mons, in Belgium, in quantity almost in- sxhaustible. Up to the present time, however, no means 1ave been found of making use of these layers on an exten- sive scale. This phosphate is found under three forms :— 1) As phosphatic limestone with 1 to 3 per cent of phos- phate of lime. It has been used several years in that region for liming the fields, after being burnt like common 'imestone. How far the phosphoric acid a&sin this manner s very difficult to say. In any case the liming of the fields nust have had some success, as it is very generally em- sloyed in Belgium for the heavy clay soils. This phos- shatic limestone is mostly found at the very surface in layers of 3 to 12 feet in thickness. . (2) As so-called nodules, a kind of coprolite form in the size of from % to 5 inches diameter. These coprolites contain 30 to 4o per cent of phcsphate of lime, and are enclosed in a kind of sandy marl containing 5 to 10 per cent of phosphate of lime, The layers have a’ thickness of 3 to g feet, and are for the greater part on the surface. The deeper layers are dug by means of small galleries. The cleaning process of these nodules is carried on in a very simple and rude manner by dry-sifting. They serve, inely ground along with very zich phosphates, for manu- ‘aéuring superphosphate. A large quantity of them is seing sent to England. The chief layers, however, are ‘formed by a kind of hard marl of brownish colour, which s found at a depth of x5 to 20 feet in a thickness of rz to 20 feet. It contains 20 to 35 per cent phosphate of Vor. XL. No. 1026. ON MANURE PHOSPHATES. By K. WALTER, Chemical Engineer, Aurelais, Belgium. Ary natural and manufadured manure phosphates may be divided into the following four groups :— {1.) Phosphates which are only soluble in acids, and not, or only very slightly, soluble in oxalate of ammonia. . (2.) Phosphates which are quite or for the greater part soluble in the oxalate. (3.) Phosphates which are quite or for the greater part soluble in citrate of ammonia; and : (4.) Phosphates which are quite or for the greater part soluble in water. The value, however, of phosphates for agricultural pur- soses cannot strictly be classed in these fourgroups. There are soils in which a given quantity of a natural phosphate of, say, 20 per cent of phosphoric acid, has the same effec as the same weight of a superphosphate of 12 to 14 per cent of phosphoric acid. Rut the price of the first would se about £1 158. or less, while the price of the latter is at least {4 per ton. On the contrary, there are other soils which absolutely require superphosphate or precipitated phosphates. In some parts of France, mostly in Nor- mandy, for instance, natural phosphates are nearly exclu- sively used for manuring purposes, and this with excellent effe@. The money values of the different manure phos. phates for different soils cannot be put into striély divided classes. Inthe excellent works of H. Toulie* the subje& >f chemical manuring is extensively treated. To the first of the above-named groups belong chiefly the richer phosphates, such as those of Canada, Curacao, Navassa, Caceres, and some other Spanish apatites; then :he phosphates of Cambridge, Nassau, Bavaria, Norway, some kinds of the phosphates of the French Ardennes, Lot, Cher; and, finally, the Russian phosphates, Those phosphates, as well as bone-ash, in which 25 per zent of their phosphoric acid is soluble in oxalate of am- monia, cannot be used with advantage for agricultural purposes, even when finely pulverised. They are nearly exclusively employed for the manufacture of superphos- phates. For the manufacture of precipitated phosphate :hey are much too expensive; natural phosphates con. taining about 35 to 40 per cent of phosphate of lime—too soor for superphosphate making—being alone profitable. To the second group belong those precipitated plios- phates which have been simply precipitated with milk of ime without observing the necessary precautions. They contain for the most part tribasic phosphate of lime with very fittle bibasic of the same. This article is not specially manu- faGured, and only appears in the market as by-produ& of glue works. It is chiefly produced in France, and the present value in the Paris market is £6 per ton with 30 per cent of phosphoric acid. This phosphate contains on an average 27 to 31 per cent of phosphoric acid, and is used successfully in France for the manufa&ure of artificial 2uanos, also for the manufature of superphosphate. It is Sut little emploved dire&ly for manurine. * Guide pour P'achat et 'emploie des Engrais Chimiques,” par H, Toulie, Pharmacien en chef de la maison municipal de “santé Administrateur Aéligué de Ja Société anonyme des produits chimiques agricoles, Cinquiéme edition; Société anonyme. 10, Quay de la Marne a Paris la Vilette, 1876. **Methode citro-uranique pour le dosage de P'acide phosphorique dans les phosphates et les engrais,” par H. Toulie, Extrait Complémentaire du Moniteur Scientifique Quesneville. Paris, au Bureau de I'Annuaire, 12, Rue de Buci: 1876.

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