bulk of their nutriment. On this basis 0-001 per cent, of any 

 ingredient would represent 112 ll)s per acre. Again if we take 

 the quantities of concentrated artificial manures which are applied 

 as top dressing and otherwise, we find tliat a soil analysis requires 

 to be carried to the third place of decimals with certainty to be 

 comparable with practical results, for some substances at all events. 

 For my part I think that this third place is about the limit to 

 whicli analyses can be carried with any degree of certainty, and 

 to do this it is necessary to carry out to the fourth and take th-e 

 nearest number in the third, and this requires that large quantities 

 be operated on which require much care and patience. 



The following are a few examples of the quantities of various 

 plant foods as they are used in high farming : — 



phosphate, soluble guano, and bone dust are applied with suc- 

 cessful results at the rate of from 2^ to 3 cwt. per acre, which 

 would be equal to about 961tjs. of phosphoric oxide per acre. 

 2nd. Nitrogen. — Two cwt. of sulphate of ammonia containing 67 

 It)s. of ammonia, produce marked results on crops, and three 

 cwt. of nitrate of soda containing about the same quantity of 

 nitrogen produces similar results. 

 In both these examples the aii.ihtical results would be lepre- 

 sented by 001% At the same tunc it must be boine in nund 

 tliat these quantities are in addition to those already present in 

 th( soil, and thit they are in a leadilv a\ ulable foim, ii d tli it 



ditieientes but controlled by a check determination, 

 one thousand grains, whilst tliose mentioned are 

 hundred The weighings -were made on a balance t 

 the tliousandth of a grain, so that they were to the tc 

 The constituents determined aie those soluble m 



