24 
BULLETIN" 150, U. S. DEPARTMENT OF AGRICULTURE. 
Table VII. — The results reported in Table VI, recalculated to the water-free 
basis. 
Character of sample. 
Nitrogen. 
Phos- 
phoric 
acid. • 
Bone 
phos- 
Tjhate 
Ca 3 (P0 4 ) 2 
Oil. 
Per cent. 
11.76 
7.20 
8.46 
Per cent. 
3.44 
4.18 
5.9S 
Per cent. 
7.50 
9.13 
13. CG 
Per cent. 
10 16 
37 22 
30 37 
8.65 
4.44 
9.70 
2S 74 
The value representing the average composition of cannery waste 
is arrived at by adding the figures for the percentage composition 
of the heads, taken twice, and of the roe and the fins and tails. The 
values for the heads are multiplied by two, because, as it will be 
remembered, the heads are estimated to make up 50 per cent of the 
waste; while the roe and the fins, with the tails, are estimated to 
constitute 25 per cent each. 
From this table it appears that the heads are richer in oil than 
the other parts of the waste. This is to be expected, and agrees 
with the facts as established practically in the rendering plants 
operating on this material. The nitrogen content of the heads is 
correspondingly low. As it is the oil which constitutes the greatest 
value among the substances recovered, this fact makes the heads 
the most valuable part. The high nitrogen content of the roe is 
to be expected, as it is made up to such a large extent of albuminous 
compounds. Its low content in oil likewise conforms to one's pre- 
conceived ideas. 
On the basis of the analysis reported in Table VI, the value of 
the raw cannery waste may be computed. 
The percentage of nitrogen, 3-.02, is equivalent to 3.67 per cent 
ammonia, NH 3 . This, in the retail market, may be expected to 
bring $3.20 per unit (a unit being 1 per cent) ; bone phosphates is 
valued at 10 cents per unit ; and oil at 30 cents per gallon. Then : 
3.67 per cent NIL., at $3.20 per unit $11. 74 
3.46 per cent bone phosphate, at 10 cents per unit .- 0. 34 
27.05 gallons oil, at 30 cents per gallon . 8. 12 
Total value per raw ton 20.20 
By present methods the manufacturers of fertilizer and oil from 
this material expect to recover about $15 in values. Present 
methods, then, can be considered as only 75 per cent efficient. In 
further substantiation of this conclusion are the results published 
by Thomas. 1 
1 A. M. Thomas, Waste in Salmon Canning Industry. Pacific Fisherman, 12, No. 2, 26 
(1914). 
