Soda- Salts in Agriculture. 311 



Chlorine combined with sodium 21"y76 



Chlorine combined with ] >otassium '386 



Chlorine combined with magncsimu "228 



Chlorine combined with calcium '388 



Total chlorine found in fixed salts .. .. 22*978 



The chlorine contained in the original 40'32 grains of chloride 

 of sodium dissolved in four deci-gallons of water amounted to 

 24"467, and as 22-98 grains of chlorine only were recovered in 

 the heated residue from four deci-gallons of salt-solution, it might 

 appear that 3*487 of chlorine had become absorbed by this soil. 

 This, however, was not the case ; for a direct determination ot 

 chlorine in a portion of the salt-solution not evaporated to dryness, 

 gave 24*402 of chlorine for four deci-gallons, or almost the 

 identical quantity present in the original salt-solution. 



No chlorine, therefore, whatever became fixed in the soil ; and 

 the question arises what had become of the missing 3*487 grains 

 of chlorine. No bases were left in the residue obtained on 

 evaporation with which the chlorine could have been xinited, and 

 the examination readily showed that this amount of chlorine did 

 not exist in a free or uncombined state. 



A minute investigation of this curious dissipation of chlorine, 

 which gradually took place during the evaporation of the liquid 

 by heating the residue to redness, showed that a portion of the 

 chlorine in the filtered salt-solution was combined with ammonia, 

 Avhich of course must have long been present in the soil under 

 experiment. 



A direct ammonia determination fully verified this supposition, 

 for, on distilling this soil with a solution of caustic potash, I 

 found that it contained 'lOS per cent, of free ammonia. For the 

 filtration experiment 3*500 grains of soil were used ; this quantity 

 consequently contained 3*605 grains of ammonia, which is more 

 than sufficient to combine with the chlorine not recovered in the 

 heated residue. The 3*487 grains of chlorine which remained 

 over and above the quantities united with sodium, potassium, 

 magnesium, and calcium, correspond to 5*255 grains of chloride 

 of ammonia, containing 1*669 of ammonia. 



Action of Salt on Peruvian Guano, 



A distinct proof is here given that common salt has the power 

 of liberating ammonia from soils that have been highly manured 

 with rotten dung, Peruvian guano, and other ammoniacal manures, 

 which in sandy soils especially exist in feeble combinations, 

 that readily undergo decomposition when brought in contact 

 with a solution of salt. In the case before us, a portion of chloride 

 of sodium acted upon these feeble ammonia combinations, pro- 



