110 ON WHEAT, OATS, BEANS, 



phate and nitrate is to be depended upon. A mixture of two 

 saline substances does not necessarily produce a less effect than 

 either of them applied singly. On the contrary, the produce is 

 usually greater,* though theoretical reasoning will satisfy us 

 that it cannot be universally so. It is unfortunate that we 

 cannot rely on single experiments, ,and are therefore compelled 

 to hold ourselves in suspense in regard even to interesting facts 

 which are not supported by adequate proof. 



2. On oats, after turnips, top-dressed 25th May 1846, by 

 Mr A. Main, East Lothian, it gave, per imperial acre f 



Light Grain. Straw. 



Nothing, . ... 42i 2| bush. 24 cwt. 



Sulphate of soda, 2 cwt. 58f 3| bush. 26j 



Sulphate of soda, 



A 1 1 1 



Animal charcoal, 



Nitrate of soda, 



Sulphate of soda, 74f ... 45f If ... 26 



Animal charcoal, 



The effect of the sulphate here was more striking than that 

 of either of the other substances applied, in so far as a single 

 experiment with each enables us to judge. The third result, 

 however, awakens suspicion. 



On oats, by Mr Fleming of Barochan in Eenfrewshire in 

 1844 



Nothing, mean of four portions, . . 51 bushels. 



Sulphate of soda, 2 cwt. per acre, . . 45 



In this negative case only one trial plot was dressed with the 

 sulphate, and the separate results from the five undressed por- 

 tions are not given. 



3. On beans, Mr Girdwood found at Corstorphine, near 

 Edinburgh, that a dressing of 2 cwt. per acre added 16 bushels 

 an acre to the crop ; and on Lord Blantyre's farm at Lennox 

 Love in East Lothian in 1843, 1 cwt. per acre increased the 

 crop from 30 to 34 bushels per imperial acre.J 



* Elements of Agricultural Chemistry and Geology, 5th Edition, p. 232. 

 f Transactions of Highland Society, January 1848, p. -176. 

 J See Appendix to the first Edition of my Lectures on Agricultural Chemistry) 

 p. 96 and 100. 



