On Liquid Manure. 523 



No. 1. — Liquid Manure from Westonbirt, near Tethury. 



A large jar filled with liquid manure from Westonbirt farm, the 

 property of Stainer S. Hoi ford, Esq., was kindly furnished me by 

 Mr. Rich, Mr. Holford's ajrent. The tank from which the liquid 

 was taken had been recently erected, and no expense appears to 

 have been spared in making- it perfectly water-tight. A perfectly 

 well-fitting cover sheltered the contents against rain, and against 

 evaporation in hot and dry weather. The contents of the tank 

 consisted chiefly of the drainings of the stables, and contained 

 comparatively little cows' or pigs' urine. On setting the liquid- 

 manure pump in motion hardly any liquid made its appearance, 

 but in its stead a thick white froth continued to flow off for 

 some minutes ; after which a dark greenish-brown, very offensive 

 and pungent-smelling liquid was pumped up. On agitating this 

 liquid it became very frothy, and at the same time gave off a 

 strong and pungent smell. The froth and pungent smell no 

 doubt were due to the evolution of carbonate of ammonia. 



At 62° Fahr. the liquid manure from .Westonbirt had a specific 

 gravity of I'OOG. 



Evaporated to dryness an imperial pint (7000 grs.) furnished 

 41-8025 grs. of solid residue (dried at 212°). 



On burning in a platinum dish this amount of solid matter 

 left 26281 of ash. A separate portion of dry residue was used 

 for the determination of the amount of nitrogen present in the 

 shape of non-volatile ammoniacal salts and nitrogenized organic 

 matters. 



A fresh quantity of liquid manure (7000 grs.) was next 

 neutralized with dilute liydrochloric acid, and thereby the volatile 

 carbonate of ammonia was fixed, and obtained on evaporation to 

 dryness on the water-bath as sal ammoniac. The addition of 

 liydrochloric acid had also the effect of decomposing humate and 

 idmate of ammonia, both of which occur in liquid manure, and 

 impart to it a more or less dark colour. The organic acids separate 

 in the form of a brownish flaky substance, whilst the ammonia 

 unites with the hydrochloric acid, forming with it sal ammoniac. 

 Liquid manure, on boiling, yields ;immonia, even if it contains 

 no free nor volatile carbonate of ammonia. This evolution of 

 ammonia arises from the decomposition of ulmate or humate 

 of ammonia — two compounds which, on boiling witli bicarbonate 

 of potash, a constituent that is always present in liquid manure, 

 yield free ammonia. 



The dry residue obtained by evaporating 7000 grains of liquid 

 manure, with the addition of hydrochloric acid, was employed 

 for determining the whole amount of nitrogen present in the 

 shape of nitrogenized matters, as well as non-volatile and volatile 



2 M 2 



