374 ANNUAL RECOKD OF SCIENCE AND INDUSTRY. 



Most prominent among these are sodium chloride (common 

 salt), magnesium chloride, and magnesium sulphate. The 

 presence more than mere traces of magnesium chloride is 

 decidedly objectionable, for its action on plant growth in 

 general is known to be destructive. It favors, also, the 

 transformation of lime in calcium chloride, and thus assists 

 in sendino^ this valuable constituent down into the drainao^e 

 water. A large admixture of common salt (some of these 

 fertilizers contain from 40 to 45 per cent.) renders them un- 

 profitable for the cultivation of the more important indus- 

 trial crops (for instance, tobacco). i^e/9^. Sec. Mass. Board 

 o/Agric, 1874-5, 358. 



GERMAN POTASH SALTS. 



The need of potash as a fertilizer has been impressing it- 

 self more and more, of late, upon farmers throughout the 

 country. The discovery of the immense deposits of potash 

 salts in the mines of Stassfurt, in Germany, and the beneficial 

 results of their use as manure in Europe, have led to the im- 

 portation of considerable quantities to the United States. 

 Unfortunately, much of this imported material has been of 

 the lower grades, which contain but little actual potash com- 

 pound, the largest portion consisting of salts of soda and 

 magnesia, and other materials of small agricultural value, 

 among the rest, chloride of magnesium, which is actually 

 harmful to vegetation. The amount of " actual potash," ^. e., 

 potassium, reckoned as potassium oxide, in the German salts 

 varies from seven per cent, in the lowest, to over fifty per 

 cent, in the highest grades. Eight samples analyzed by Pro- 

 fessor Goessmann contained respectively 7.97, 7.56, 8.72, 8.37, 

 9.18, 10.14, 16.21, and 50.30 per cent, of potassium oxide. 

 The three lowest results were from fertilizers represented to 

 contain 32.34 and 41 per cent, respectively. The two highest 

 were nearly or quite equal to the dealers' guarantee. Not 

 only were the poorer articles deficient in potash, but they 

 contained considerable chloride of magnesium ; and, further, 

 the larger proportion of their potassium proved, as Professor 

 Goessmann states, to be present in the form of chloride of 

 potassium, and they belong consequently, without exception, 

 to those low grades of German potash salts which are com- 

 monly called "Dung salts." ... To buy these low grades of 



