16 



so small in fact that it only suffices for the production of an 

 average crop in favorable seasons. But as really favorable 

 seasons are again the exception rather than the rule, the natural 

 supply proves generally inadequate. If it does not rain for a 

 fortnight the plants stop growing, because they cannot take up 

 phosphoric acid. When the next rain comes they are ready, 

 not only for the amount which the earth can give them daily, 

 but for a great deal more, and unless they find this "more " in 

 available form in the soil, the extra exertion of the plants to 

 make up for lost time are put forth in vain. Such contingencies 

 render it therefore necessary to be most liberal with phosphoric 

 acid; it should be given to every crop in abundance, so that a 

 surplus is always in the ground, because whenever plants get 

 abnormally hungry, as is the case after a rain following a spell 

 of dry weather, their abnormal appetite can only be satisfied by 

 such a surplus. 



All agricultural chemists agree on this point, all recognize 

 and consequentiy advise the farmer not to be sparing with the 

 fertilization with phosphoric acid; first, because its presence is 

 indispensable for any large crop; secondly, because it is never 

 lost, but benefits succeeding crops. 



WHEREIN CONSISTS THE POTASH 

 QUESTION. 



After these remarks about nitrogen and phosphoric acid, the 

 -very important practical question arrests our attention: How 

 can nitrogen-gatherers be made nitrogen-hungry? and this 

 brings us to the potash question, a subject which during the last 

 eight or ten years has forced itself upon all scientists. Prac- 

 tical results obtained by practical men, who, while highly 

 intelligent farmers, did not claim to be scientists, appeared to 

 establish, a set of facts hitherto unknown. The facts were 

 irresistible and induced Prof. Maerker, Prof. "Wagner and others 

 to investigate the subject thoroughly, with a view of framing a 

 scientific answer to the practical answer which experience had 

 furnished to Schultz on his poor land in Lupitz, and to Rimpau 

 on the peat soil of Cunrau. As Dr. Emil Wolff, Professor in 



