56 



acre so that the sulphate of ammonia supplied more 

 nitrogen than the nitrate of soda by about 5 Ibs. per acre. 

 The following were the weights of potatoes grown per 

 acre : 



TABLE XXXV. 



The difference in favour of sulphate of ammonia when 

 artificials only were used is remarkable, and is possibly 

 partly due to accidental circumstances. That an actual 

 superiority of sulphate of ammonia was shown in this 

 experiment, may be inferred from the fact that the highest 

 produce of any of the plots many of which are not in- 

 cluded above was that from sulphate of ammonia with 

 farmyard manure and minerals. Nitrate of soda was used 

 in a number of different combinations, but at best gave a 

 crop nearly 7 cwt. worse than the best sulphate crop. 



So as to avoid giving a partial view of the case, one 

 other experiment may be quoted. This was carried out 

 on two farms in Cumberland and Durham, in 1896, under 

 the direction of the Durham College of Science. The 

 artificial nitrogenous manures, it must be noticed, were 

 employed so as to give equal quantities of nitrogen, not in 

 equal weights of the manures. The following are some of 

 the results obtained : 



TABLE XXXVI. 



Manures. 



Large. 



Small. 



Total. 



