FISH POMACE AND GUANO. 225 



filtration through bone-black, and that bone-black is made by 

 calcining bones. The gelatinous matter in the bones is thus con- 

 verted into charcoal, and the phosphate of lime remains in a 

 very porous condition. This substance is a wonderful absorbent 

 of the coloring matter which the refiners desire to remove from 

 the sugar. The refuse of refineries, therefore, must be a valu- 

 able fertilizer. It is pure burnt bone, with a certain amount of 

 carbonaceous and nitrogenous matter obtained from the crude 

 sugar. I should hope that Mr. Bradley would put a large 

 amount of it into his phosphate, especially if its solubility was 

 increased by a suitable amount of sulphuric acid. 



Then in regard to his use of fish pomace. As I understand 

 it, this fertilizer is advertised as an ammoniated phosphate. It 

 is not designed simply to supply certain desirable manurial 

 matter, but also to quicken vegetable growth. It is a partially 

 ammoniacal or nitrogenous substance, and so is a substitute to 

 a certain extent for barnyard manure. ,Now the fish pomace 

 undoubtedly is a vegetable ingredient in a phosphate of this 

 description, and by its fermentation and supply of ammonia 

 may prove to be actually worth all its cost in the form in which 

 it is applied in Bradley's phosphate. It has been said here that 

 Peruvian guano is put into Bradley's phosphate, to a certain 

 extent, and into some other commercial fertilizers. It is not 

 probable the manufacturers use very much of the best Peruvian 

 guano, but this leads me to a subject which may be of impor- 

 tance to the farmers here who buy this article. In the valley 

 of the Connecticut a great quantity is used, especially in the 

 cultivation of tobacco. Nearly two hundred tons were bought 

 by one man and brought to the depot in Amherst this year. 

 Therefore it becomes a momentous question, what this sub- 

 stance is which we get as Peruvian guano, and for which we 

 pay sucli an enormous price. Having the facilities for testing 

 such things at the Agricultural College, we took some specimens 

 from different purchasers and subjected them to analysis, and 

 these analyses we shall probably publish. We find a surprising 

 diversity in the composition of different samples, and some are 

 certainly not worth one-half what they cost. The Chairman 

 (Mr. Davis of Plymouth) has' asked whether chemists gener- 

 ally have faith in chemical science ; whether farmers may 

 believe that the deductions of Dr. Nichols are reliable. In 



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