288 



and thereby rendered his hiud incapable of bearing grain for years. It 

 contains, according to Davy, 730 parts of that element in 10,000. In 

 the same quantity of the ashes of fumitory were found 790 parts. Pro- 

 fessor Way, in 100 parts of ashes, found potash in the follo\dng propor- 

 tions: 



Of the potato 50.88 parts. 



Of the red clover hay - - 14.85 parts. 



Of tlie white clover hay 14.33 parts. 



Of the the long red mangold root 21.63 parts. 



Of the Skirving's Swede bulb 36.10 parts. 



Professor Voelcker thus remarks upon experiments which seemed to 

 prove the value of salts of potash upon potatoes, clover, beets, and 

 turnips : 



In several experiments, tried on poor, sandy soils daring the. past season, the addition 

 of crude potash salts to superiihosphate of lime had a very marked and deeidedly ben- 

 eficial effect on the potato crop, and also on Swedes. Even when api)lied alone, crude 

 potash salts benefit materially root crops growing on jioor, sandy land. The same ben- 

 eficial ettect I find, by direct experiments, cannot be obtained by the application of 

 common salt, showing that soda is a much lees valuable fertilizing constituent than 

 potash, and incapable of replacing the functions of the latter in the vegetable economy. 



Hitherto the price of potash has stood in the way of its being employed on an ex- 

 tended scale in agriculture. Even in its cheapest form — that of crude German potash 

 salts — potash was too dear for practical application in agriculture. But as potash will, 

 no doubt, be extensively used in agriculture, if it can be had at a cheap rate, I have 

 pleasure in directing attention to a mineral called kainite, which is found in the neigh- 

 borhood of Staufnrth, in Saxony, and which, in round numbers, contains 24 per cent, 

 of sulphate of potash and 12 per cent, of sulphate of magnesia. This saline mineral 

 can now be obtained in England, in a finely ground condition, ready for mixing with 

 other artificial manures, at about £3 3x. per ton, and probably less when considerable 

 quantities are required. From three to four hundred-weight of ground kainite, mixed 

 with an equal quantity of superphosphate of lime, per acre, htus been found of great utility 

 in the sugar-beet growing districts of North Germany; and I have no doubt will be 

 found equally useful iu England, where root crops are intended to be raised upon 

 naturally poor or upon exhausted sandy soils. The crop, however, most likely to be 

 greatly benefited by this potash mauure is the potato. 



On light soils, I would strongly recommend, as a manure for potatoes, the following 

 mixture : four to five hundred-weight of kainite, (crude German potash,) four hundred- 

 weight of Penivian guano, and four hundred- weight of superphosphate of lime. 



Professor C. W. Johnson thus sums up the results of experiments, 

 instituted at the suggestion of Professor Voelcker, at Escrick Park, in 

 the season of 1869, upon mangolds. 



The mangolds were sown on May 11, 1869, on a barley stubble in 1868. The soil ot 

 the experimental field was of a light, sandy character, and, though naturally poor, it 

 was in a good agricultural condition, as the produce from the unmanured plot showed. 



The mangold crop was taken up, topped, tailed, and weighed on the 11th November, 

 1869, when the following results were obtained : 



No manure 



Miner.al superphosphate, 3 cwta 



Mineral superpho.sphate, 3 cwt«., and potash 8alt.s, 2 cwts 



Mineral suptnphosphat e, 3 cwts., and Peruvian guano, 1 cwt 



Peruvian fruano, 3 cwts - 



No manure 



Mineral superphosphate, 3 cwts. ; ]>otash salts, 2 cwts ; and sulphate of ammonia, 



1 cwt 



Rotten dung, 20 tons 



Mineral superphosphate, 3 cwts. ; potash salts, 2 cwts. ; and nitrate of soda, 



1 cwt 



Rotten dung, 10 tons, and mineral superphosphate, 1 J cwt 



Bone dust, 3 cwts., and mineral superphosphate, l.J cwt 



