BULLETIN OF THE BUSSEY INSTITUTION. 19 
and in bone-meal, and to that of “unknown quality,” are probably 
much teo high for regions like New England, where abundant stores 
of nitrogen in the form of peat and pond-mud are accessible to most 
farmers, and can easily be made “active” and available as plant-food 
by fermentation in the compost-heap. 
As regards the nitrogen in the superphosphates analyzed, it is 
doubtless to be referred in most instances to an admixture of rough 
“fish-scrap,’ otherwise called ‘fish-pomace,” or ‘ pogy-chum,” which 
is the residue left after the expression of oil from the boiled flesh of 
the fish (Alosa menhaden) known as pogy, menhaden, or hardhead. 
For several years past this material, brought in bulk from the State 
of Maine, has been procured by farmers in the vicinity of Boston at 
the rate of $15 perton. A sample of this product obtained from Mr. 
William L. Bradley of Boston was found to contain : — 
mn lw, wt, (88,68 
Volatile matter (beside moisture) .  . 51.37 
Ash e e e e 3 e ° ° 14.95 
—— 100.00 
Of matters valuable as manure, the specimen contained : — 
Phosphoric acid . . ; : : : 5.59 
ital Ribbon: 6.49 ; ammonia, 1.85%, i.e. nitrogen. wef WB 
aw nitrogen not in form of ammonia . . 4.90 
There was sand, &c., to the amount of one per cent. 
In a ton of such fish-scrap there would be 112 pounds of phosphoric 
acid, worth from $5.60 to $6.72, according as the lower or the higher 
estimate of the cost per pound of insoluble phosphoric acid were 
adopted ; and 30.4 pounds of nitrogen in the form of ammonia worth 
$9 on the estimate (thirty cents per pound) above given. Hence the 
ninety-eight pounds of nitrogen not in the form of ammonia contained 
in a ton of fish-scrap would cost the purchaser either forty cents or 
Jess than nothing, according as one or the other valuation of the phos- 
phoric acid were adopted. | 
In spite of the apparent absurdity thus shown of the high estimate 
{twenty cents per pound) given above for the pound of nitrogen of 
unknown quality, and of my conviction that the addition of rough 
nitrogenized materials to superphosphates at the manufactory is a 
