No. 4.] THE HARVEST OF THE SEA. 127 



The Economic Question. 

 We find by the foregoing table that sufficient plant food 

 (excepting potash) was taken from the sea in eighteen years 



for 



700,000,000 bushels of potatoes, or 

 160,000,000 bushels of corn, or 

 108,000,000 bushels of wheat, or 

 5,000,000 tons of hay, 



with phosphoric acid to spare in each case. 



An examination of the Association Records shows that the 

 largest amount of plant food obtained from the sea was in 

 1884, when there were taken from our Atlantic waters nearly 

 69,000 tons of fish yielding over 10,000,000 pounds of nitro- 

 gen and 9,000,000 pounds of phosphoric acid ; or enough 

 nitrogen and phosphoric acid to fertilize fully 



200,000 acres of corn of 50 bushels each, or 

 500,000 aci-es of potatoes of 100 bushels each, 



with phosphoric acid to spare in each case. 



According to the AVashinofton authorities, we cultivated 

 in New England in 1891 250,252 acres of corn, which 

 yielded 9,284,000 bushels. A further calculation shows 

 that in one year we took out of the sea sufiicient plant 

 food, excepting potash, to fertilize nearly all the corn 

 grown in New England for 1891. 



To put it in another way, enough nitrogen, the most costly 

 part of a fertilizer, was taken from the sea in 1884 to furnish 

 the nitrogen for all the fertilizers sold that year in the New 

 England and Middle States, — fully 200,000 tons. 



scrap reported bj' the Menhaden Association is 353,911 tons; amount of acid scrap, 

 537,432 tons; total, 891,343 tons. 



The dry scrap was estimated at 8 per cent of nitrogen and 7 per cent of phosphoric 

 acid, although the average of a mmiber of tests showed nearlj' half a per cent higher 

 in each case. The acid scrap was figured at 6 per cent of nitrogen and 4 per cent of 

 phosphoric acid, and the calculation was made at 16 cents per pound for the nitrogen 

 and 7 cents per pound for the phosplioric acid, no allowance for the reverted phos- 

 phoric acid in the acid scrap. It is claimed by some that these figures are too high, 

 but, since the record covers eighteen j'ears, it would have been fair to take the 

 average price for that time, which, according to the reports of the inspector of 

 fertilizers of Massachusetts, averaged, in the case of nitrogen, 20^ cents per pound. 

 The question turns, however, not so much upon the commercial value of the plant 

 food as upon how far it will go in raising crops, as will be seen iu the discussion of 

 the economic question, pages 127 and 128. 



