FERTILIZERS. 17 



combined with oxalic, tartaric, silicic, and sulphuric acids. 

 When wood is burnt, these acids are decomposed; and, 

 the potash combining with carbonic acid, we have the 

 common form of carbonate of potash. Potash is not only 

 one of the three essentials for all plant-growth, but it is 

 also found in the fruits, vegetables, and grains. The 

 grape, the apple, the potato, are illustrations. The ashes 

 of bean and pea vines, the potato-vine, and beet-leaves, 

 are especially rich in potash ; while corn-cobs and aspara- 

 gus stalks yield an enormous proportion, though but a 

 small amount compared with their bulk. The principal 

 sources from which we obtain potash are, India, from 

 which comes the nitrate of potash ; Germany, from which 

 come the sulphates, muriates, kainite, kruget, etc. (all of 

 them products of the famous Stassfurt deposit), wood 

 ashes (which includes those from the brick-kiln and lime 

 kiln), burnt tan, logwood, etc., and a limited amount 

 from the burnt hulls of cotton-seed. The potash in all 

 these forms comes originally, as we have already stated, 

 from the Creator's great storehouse, the felspar and mica 

 bearing ledges, with the soils formed from their disintegra- 

 tion and decomposition. From the nitrate of potash is 

 made the saltpetre of commerce. Being costly, it is rarely 

 used for agricultural purposes, though, to a limited extent, 

 a waste product enters the market. 



The Stassfurt mines of Germany were originally opened 

 for salt-mines ; and what was at first looked upon as a 

 worthless waste, the wand of Chemistry pointed out as by 

 far the most valuable product. These mines make, I am 

 informed, the centre of a vast basin, many miles in diam- 

 eter, which is believed to have been the bed of an ancient 

 salt sea. The various salts, from their composition and 

 the order of their formation, are believed by men of science 

 to have resulted from the drying-up of this sea. The de- 



