282 FIRESIDE SCIENCE. 



pecially on moist land. But enough has been said 

 to show that each variety of plants demands peculiar 

 kinds of food, and unless this is supplied by the soil, 

 or through our agency, it is impossible for them to 

 flourish. 



There has never been a time when soil cultiva- 

 tion, as a pursuit, was more hopeful or promising 

 than the present. We have just learned the impor- 

 tant fact that an abundance of plant food has been 

 stored up for our use in mines and rocks, and that 

 we have only to reach out our hands and take all 

 that we require. Ten years ago who could have 

 dreamed even of such vast deposits of potash as 

 have been opened up to us at the Stassfurth salt 

 mines in Germany. Some idea of the supply may 

 be formed from the fact that at the present time 

 more potash is furnished from these mines than 

 from the wood-ash sources of supply of the whole 

 world. Only about 13,000 tons of potash were 

 sent to market from the United States and British 

 America in 1870, and yet from Stassfurth, where 

 a dozen years ago it was not supposed that a single 

 ton could be procured, 30,000 tons of the muriate 

 of potash were manufactured and supplied to con- 

 sumers upon both continents, during the past year. 

 The surface salts at these mines, which hold the 

 potash, are practically inexhaustible, and millions 

 of tons will be supplied in succeeding years. No 

 doubt our own salt mines will be found upon care- 



