486 On the Groicth of Barley hy different Manures, Sfc. 



yielded a less result than the nitrate in relation to the assumed 

 amount of nitrogen supplied, gave 216 lbs. less corn, and about 

 252 lbs. less straw, than the farmyard manure. 



Unless, then, we are to attribute some important influence to 

 the soda of the nitrate, or to the sulphuric acid and chlorine of the 

 ammoniacal salts, we have here, by the supply in manure, of 

 available nitrogen alone ( = about 50 lbs. ammonia per acre per 

 annum), in one case even more, and in the other somewhat less, 

 of annual total produce, than by the whole of the constituents of 

 the annually supplied 14 tons of dung. 



In experiments 9, 10, and 11, we have the same amount of 

 ammoniacal salts as in No. 8, but now in conjunction with one 

 or other of the respective mineral manures of Nos. 4, 5, and 6. 

 The addition of the " mixed alkalies " (salts of potash, soda, and 

 magnesia) to the ammoniacal salts, raises the average annual 

 produce by 81 lbs. of corn and 246 lbs. of straw. Estimating 

 the result the converse way, the addition of the ammoniacal salts, 

 as in No. 9, to the " mixed alkalies^^ as in No. 4, has given an 

 increase of 645 lbs. corn and 988 lbs. of straw. Or, if we com- 

 pare the result of the combination of the ammoniacal salts and 

 the " mixed alkalies " with the unmanured produce, the com- 

 bination has given an increase of 687 lbs. of corn and 1024 lbs. 

 of straw, against 822 ll)s. increase of corn and 1030 lbs. of straw 

 by the farmyard-manure. Supplied nitrogen (about 41 lbs. per 

 acre), and salts of the fixed alkaline bases, have therefore 

 nearly reached the result of 14 tons of farmyard-manure. 



.In experiment No. 10 superphosphate of lime is the mineral 

 manure added to the ammoniacal salts of No. 8. The addition 

 of the superphosphate of lime increased the produce by 354 lbs. of 

 corn and 636 lbs. of straw (=r 990 lbs. total produce) over that 

 by the ammoniacal salts alone. Cakulating conversely, the 

 addition of avimoniacal salts to superpliosphate of lime gave an 

 average annual increase of 797 lbs. of corn and 1328 lbs. of straw 

 over the produce of the latter alone, against an increase of 606 

 lbs. of corn, and 778 lbs. of straw, over the unmanured produce 

 when the same amount of ammoniacal salts were used alone. 

 Again, by the conjoint action of ammoniacal salts and super- 

 phosphate of lime, we get an average annual increase over the 

 unmanured produce, of 960 lbs. of corn and 1414 lbs. of straw, 

 against an increase of only ^'22 lbs. of corn and 1030 lbs. of 

 straw, by the farmyard-manure. 



In experiment No. 11 we have, in addition to the same amount 

 of ammoniacal salts as before (containing about 50 lbs. of am- 

 monia), both the ^'- mixed alkalies'" and iXie superphosphate of lime^ 

 as in No. 6. The increase of No. 11 over No. 10 by the addi- 



