24 Liquid Manure. 



to all previous experience, such a soil possesses in an eminent 

 degree the power of absorbing manuring matters ; it might be 

 therefore expected that the whole of the ammonia contained in 

 such a weak solution as the Tiptree liquid manure would 

 be removed by such a soil when used in the proportion of 

 2 of soil to 7 of liquid. The same might be suspected with 

 regard to potash and phosphoric acid. However, this experiment 

 shows that a soil distinguished for its great power of absorbing 

 soluble fertilizing matters does not entirely remove them even 

 from a very dilute solution. As the subject is of considerable 

 scientific interest, I may be allowed to examine the results 

 obtained in this experiment a little more in detail, and there- 

 fore notice : 



1. Although only 7*7 grains of organic matter were present in 

 the Tiptree liquid manure, Mr. Mechi's soil removed only 2J in 

 round numbers, leaving 5j dissolved in the liquid. 



2. In the preceding experiments 



1000 grs. of soils from College Farm absorbed .. *738 of ammonia. 



pasture land *737 



sterile sandy land .. .. '121 



fertile loamy land .. '487 



None of these soils contained so much clay as Mr. Mechi's soil, 

 but, nevertheless, they all absorbed more ammonia than the 

 stiff clay soil in the experiment with a very dilute liquid. There 

 are only 3'36 grains of ammonia in a gallon of the Tiptree 

 liquid manure, which certainly might be expected to be ab- 

 sorbed by 20,000 grains of soil ; for, if so, 1000 grains would 

 only have absorbed '168 of a grain of ammonia. Nearly the 

 same quantity of ammonia, we have seen, was absorbed by a 

 soil consisting almost entirely of sand, which, we know, does 

 not possess in a high degree the power of retaining ammonia. 

 Notwithstanding the large proportion of clay and the small 

 quantity of ammonia in the liquid manure from Tiptree Hall 

 Farm, only 1*81 grains of ammonia were absorbed by 20,000 

 grains of soil, and 1*55 grains remained in the liquid after 

 three days' contact with it. 1000 grains of this soil thus absorbed 

 only *0905 of a grain of ammonia. 



There can be no doubt that a stronger solution of ammonia 

 passed through Mr. Mechi's soil would have parted with a much 

 larger proportion of ammonia than in the present experiment. A 

 distinct proof, then, is here afforded that soluble manuring 

 matters like ammoniacal salts in contact with soil are not ren- 

 dered entirely insoluble. In this experiment we have the most 

 favourable condition for the complete absorption of ammonia, 

 yet nearly one-half of the ammonia is left in the liquid after 

 contact with the soil : thus showing plainly that the compounds 

 which we cannot doubt are formed in clay soils, when soluble 



