AGRICULTURAL, ANALYSIS 



of salts of different kinds. There may also have been at the 

 bottom of this basin some subterranean heat such as is found in 

 certain localities where boric acid is deposited. 



Whatever be the explanation of the source of the heat, it will 

 be admitted that at the end of the permian period there was 

 thrown up to the northeast of the present saline deposits a ridge 

 extending from Helgoland to Westphalia. This dam estab- 

 lished throughout the whole of North Germany saline lagoons 

 in which evaporation was at once established, and these lagoons 

 were constantly fed from the sea. 



There was then deposited by evaporation, first of all, a layer 

 of gypsum and afterwards rock salt, covering with few excep- 

 tions the whole of the area of North Germany. 



But around Stassfurt there occurred at this time geologic dis- 

 placements, the saline basin was permanently closed and then by 

 continued evaporation the more deliquescent salts, such as poly- 

 halit, kieserit, and carnallit, were deposited. 



These theories account with sufficient ease for the deposition 

 of the saline masses, but do not explain why in those days the 

 sea water was so rich in potash and why potash is not found in 

 other localities where vast quantities of gypsum and common 

 salt have been deposited. It may be that the rocks composing 

 the shores of these lagoons were exceptionally rich in potash 

 and that this salt was, therefore, in a certain degree, a local 

 contribution to the products of concentration. 



416. Sources of Supply. The Stassfurt deposits, which have for 

 many years been almost the sole source of potash in fertilizers, 

 were first known as mines of rock salt. In 1839, having pre- 

 viously been acquired by the Prussian treasury, they were aban- 

 doned by reason of the more economical working of rock salt 

 quarries in other localities. It was determined thereafter to ex- 

 plore the extent of these mines by boring, and a well was sunk to 

 the depth of 246 meters, when the upper layer of the salt deposit 

 was reached. The boring was continued into the salt to a total 

 depth of 581 meters without reaching the bottom. The results 

 of these experiments were totally unexpected. Instead of get- 

 ting a brine saturated with common salt, one was obtained con- 



