3G2 
of animal products, will recommend itself to the agriculturist. 
At present, peat charcoal is not obtainable under 50s. per 
ton, and if to this be added an average cost of carriage, the 
price becomes raised to 60s. per ton. I question whether 
any profit is to be derived from its use at this price, except 
in such a case as its admixture with guano ; this I 
consider to be about the best practical application of this 
substance as a manuring agent. Mixed with guano, peat 
charcoal is of very great value, inasmuch as it serves the 
useful purpose of absorbing and storing up the ammonia con- 
tained in this valuable manure, and giving it out again to the 
plant in a less rapid manner than unmixed guano would 
under similar circumstances ; the benefit arising from this 
slower liberation of ammonia appears to be this, that whereas 
in pure guano, the plant is often stimulated in its growth 
before it can take up a due quantity of another important 
constituent of guano, viz., the phosphoric acid ; in the case 
of charcoal guano, the supply of ammonia keeps a more 
even pace with the absorption of phosphoric acid, and thus 
a more healthy and vigorous development of the plant takes 
place. 
When peat charcoal is made for £l per ton, which 
Mr. Yarrow says it can, and which I think it may be by good 
management, its application mixed with night soil, &c, would, 
no doubt, be amply remunerative. There can be no question 
as to the value of such a manure ; the only question is, which, 
in fact, is the question of questions, will it produce as good 
results as guano, sulphate of ammonia, coprolite, &c, of 
equal cost ? The sale of the peat charcoal manure, the 
produce of the Aylesbury filter tank at £3 per ton, proves 
that it will, otherwise the Buckinghamshire farmers would 
not buy it. 
