70 THE AMERICAN FARMER. 



and brain. These famous German potash mines are located near the Hartz Mountains, 

 partly in Prussia and partly in the small Duchy of Anhalt. These include the mines of 

 Stassfurt proper, the contiguous mines at Leopold shall, and those more recently opened about 

 ten miles distant at Westeregeln. According to the best authority, the deposits of this 

 region consist chiefly of the various compounds of sodium, potassium, magnesium, and lime, 

 with sulphuric acid, and chlorine. The larger proportion, however, consists of chloride of 

 sodium, or rock-salt, which seems to be stored there in an inexhaustible supply. Lying on 

 the top of the rock-salt deposit are various mineral salts, such as kieserite, polyhalite, kainite, 

 carnallite, etc. The total area of this salt-basin is supposed to be about six hundred square 

 miles; the upper surface of the deposit at Stassfurt being from 350 to 830 feet from the surface. 

 It is stated that in the year 1856 the miners penetrated to the depth of 1,856 feet, finding 

 pure rock-salt in a seemingly inexhaustible supply as they bored down, and that they then 

 said, &quot; We have made the depth equal to the date; the salt layer seems to be as immeasurable 

 as the centuries. Let up stop.&quot; Prof. Atwater says of these mines: 



&quot; It is a comparatively few years since the deposits were discovered, but the products 

 have come into very general use in Germany and other parts of Europe, and are being im 

 ported quite largely into this country. When rightly used on soils deficient in potash, they 

 are very profitable fertilizers. A vast amount of experimenting has been done with them, 

 more in Germany than anywhere else. The results indicate that the usefulness of these salts 

 as fertilizers depends not only upon the character of the salts themselves, of which there are 

 various grades, but also on the kind of soil, the mode of application, and the kind of crop. 



Composition of German Potash Salts. The potash salts, as taken from the 

 mines, contain only small proportions of potassium compounds, the bulk consisting of materials 

 which have comparatively little agricultural value, and are sometimes positively injurious. 

 In the early history of the Stassfurt potash industry, many experiments were made with 

 these crude salts, but, with the exception of the Kainit, their use has been attended perhaps 

 oftener by failure than by success. It has been found necessary to subject them to chemical 

 treatment, by which the potash compounds are more or less completely purified. This is done at 

 factories near the mines, where immense quantities of the potash salts are manufactured for 

 technical and agricultural uses. As prepared for market, the potash fertilizers contain potas 

 sium in the form of either chloride of potassium or sulphate of potash, and, along with 

 these, chloride of sodium, chloride of magnesium, sulphate of soda, and sulphate of magnesia, 

 and small quantities of other materials. 



The basis of potash compounds is the element Potassium. This, combined with oxygen, 

 forms potassium oxide, or potassa, or, in familiar language, potash. The same term, potash, 

 is applied to two other potassium compounds. One, which may be considered as a compound 

 made up of potassa and water, is known in the chemical laboratory as potassium hydrate, 

 and, in common language, as caustic potash. The other is a compound of potassa with car 

 bonic acid, and is commonly called carbonate of potash. The ordinary potashes and pearl- 

 ashes, prepared from the lye of wood-ashes, are more or less impure carbonate of potash. 

 Potassium, combined with chlorine, forms potassium chloride, commonly called chloride of 

 potassium, or muriate of potash. Potassa united with sulphuric acid forms potassium sul 

 phate, or sulphate of potash. By adding to ordinary potash lye from ashes, a proper amount 

 of sulphuric acid, and boiling the liquid down, we might, with proper care, obtain a solid 

 substance, which would be a sulphate of potash. If we were to use hydro chloric (muriatic) 

 acid instead of sulphuric, we should obtain a chloride of potassium, or muriate of potash. 

 Other elements, as well as potassium, combine with sulphuric acid and chlorine to form 

 sulphates and chlorides. Sodium chloride is common salt. Sulphate of soda (sodium eul 

 phate) is known as Glauber s salt, and sulphate of magnesia as Epsom salts. The German 

 potash salts consist of potassium chloride and sulphate, mingled with more or less of the just- 



