EXPERIMENTS WITH SULPHATE OF SODA. 109 



4. Results of experiments with the sulphates of potash and 



In consequence chiefly of the high price of sulphate of potash, 

 few experiments have, I believe, been made with it, and I am 

 consequently unable to insert any illustrations of the nature of 

 its action. Numerous trials, however, have been made with 

 the sulphate of soda, of which I quote the following : 



1. On wheat after potatoes by Mr Main, East Lothian, in 

 1846. Applied on the 25th of May, as a top-dressing, alone 

 and in conjunction with animal charcoal, it gave, per imperial 

 acre 



Grain. Straw. 



Nothing, . . . 37| bushels. 29 cwt. 



Sulphate of soda, 2 cwt. 42 ... 38 



Sulphate of soda, 1 ... ) ^ ^ 



Animal charcoal, 1 ... j 



By the same Mr Main, in 1847, on two varieties of wheat. 

 a On Taunton Dean wheat, top-dressed 1st February, and 

 compared with Peruvian guano 



Grain. Straw. 



Nothing, ... 27^ 19^ cwt. 



Sulphate of soda, 2 cwt. 32 24f ... 



Peruvian guano, 2 ... 29^ 24 



The superiority of its effects to those of the guano is pro- 

 bably to be attributed to the state of the land. 



b On Hopeton wheat, in 1847, compared with nitrate of 

 soda 



Grain. Straw. 



Nothing, . . 40 bush. 27 cwt. 



Nitrate of soda, . 3 cwt. 50 ... 39^ ... 



Sulphate of soda, . 3 ... 46 ... 33| ... 



Sulphate of soda, . 1^ ... ) 3 



Nitrate of soda,t . l| .... J 



The reader will no doubt regret with me that duplicate or 

 triplicate experiments had not enabled us to judge how far the 

 apparently contradictory result obtained from the mixed sul- 



* Transactions of Highland Society, January 1848, p. 175. 

 f Transactions of Highland Society, March 1849, p. 530. 



