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Ammonium chloride in cahxallite. — The presence of nitrogenous compounds 

 in Stassfurt potash salts has recently been recognized. Ammonium chloride was 

 some time ago found to occur frequently in rock salt and in the manufactured pro- 

 ducts. W. Diehl found 0.01 per cent of ammonium chloride in crude camallite, and 

 0.015 per cent in artificial carnallite. He says that in the concentration of carnal- 

 lite brines a deposit is sometimes formed containing 80 to 90 per cent of ammonium 

 chloride. More recently Neimke, of Leopoldshall, reports finding 0.8 per cent of 

 ammonium chloride in artificial carnallite. White carnallite furnishing 22 per cent 

 of muriate of potash contained 0.25 to 0.27 per cent of ammonium chloride, while the 

 colored salt, with 18 per cent of muriate of potash contained only about 0.09 per 

 cent of ammonium chloride ; and the artificial carnallite made from the white salt 

 contained 0.8 per cent. According to a very exact determination on a large number 

 of samples of the Neustassfurt salt the crude carnallite contains up to 0.08 and the 

 artificial up to 0.012 per cent of ammonium chloride. Concerning the origin of this 

 ammonia, it has been suggested that it may be traced to organic materials present at 

 the time the salt beds were formed, which by putrefaction yielded ammonia. 



Lime on clay soils. — The beneficial efi'ects of an application of lime to clay soils 

 is explained by M. Johnstone {Xaturw. Rundschau, 1891, p. 323) as follows: Clay is 

 a productof the decomposition of silicates which contain alkalis and alkaline earths, 

 besides aluminium. Thus a clay derived from feldspar might contain the hydrated 

 silicate of aluminium plus potassium silicate (or sodium or calcium silicate). Clay 

 particles of this composition lose their potash when treated with carbonic acid 

 water. The author's experiments indicated that the resulting potash compound was 

 a carbonate when an excess of carbonic acid was present, and a soluble silicate when 

 insufficient carbonic acid was present. If lime is present in the latter case it unites 

 with the silicic acid and the potash is freed to combine with any other available acid 

 forming a salt useful to the plant. Hence, the action of lime on clay consists in com- 

 bining with the silicic acid and setting the potash free. 



Milk cake. — Wilhelm Rehustrom of Sweden proposes to utilize the skim milk 

 from the cream separator for the preparation of a feeding cake for animals from the 

 casein it contains. The process is briefly described as follows: The precipitated 

 casein is dried, ground, mixetl with various nitrogenous feeding stuffs, and pressed 

 into cakes. These cakes, it is claimed, furnish an exceptionally valuable feeding 

 stuff for milch cows and other animals. The process is said to have been patented in 

 several countries. 



17450_Xo. 8 6 



