Experiments upon Swedes. 173 



great difference in the amount of ammonia in this and the pre- 

 ceding guano. 



Notwithstanding the larger percentage of soluble phosphate, 

 the guano No. 2 has not given quite so good a result as No. 1, 

 and it appears to me that this may have been due to the sudden 

 check which the crop sustained, and which will be felt all the 

 more, the more rapid the progress has been at first. 



Plot III. — Manured with li cwt. of phospho-Peruvian guano 

 per acre. 



Produce 8 tons 19 cwt, 5 lbs. 



Increase per acre . . 2 tons 7 cwt. 1 qr. 9 lbs. 



Half the quantity of the same guano used in Plot No. 1, it will 

 be perceived, gave very nearly the same increase as the larger 

 quantity, which is a convincing proof of ,the fact that the larger 

 amount of phosphates in these manures has not had a fair chance 

 of producing the effect which in more favourable seasons they 

 would no doubt have produced. 



Plot IV. — Manured with phospho-Peruvian guano, No. 3, at 

 the rate of 3 cwt. per acre. 



Produce .. 10 tons 3 cwt. 5 lbs. 

 Increase .. 3 tons 11 cwt. 1 qr. 9 lbs. 



No difference in the appearance of this and the preceding plots. 

 The composition of this guano was found as follows : — 



Moisture 10-07 



Organic matter and ammoniacal salts IG'97 



Bi-phosphate of lime 9'8y 



Equal to bone-earth, rendered soluble by acid .. .. (15*42 , 



Insoluble phosphates,! Phosphoric acid .. 18'79'i o-.pi 



consisting of : ..\Lime 18"82/ 



Hydrated sulphate of lime 16"98 



Alkaline salts 3"13 



Insoluble silicious matter 5*35 



100-00 



Containing nitrogen 2' 12 



Equal to ammonia 2-57 



Percentage of phosphates rendered soluble 15 42 



„ of insoluble phosphates, calculated as tribasic\ 4,). 71 



phosphates of lime / 



Total phosphates .. .. 5(j-l:! 



This guano resembles in composition the one used in Plot I., 

 but contains less soluble and more insoluble phosphate. 



Plot V. — Manured with phospho-Peruvian guano, No. 4, at 

 the rate of 3 cwt. per acre. 



Produce .. 10 tons 5 cwt. 2 qrs. 24 lbs. 

 Increase .. 3 tons 14 cwt. 



