220 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



" 10,000 fish, on the average, yiekl 1 ton of half dry scrap, containing 

 40 to 50 per cent, of water. 



"15,000 fish, on the average, make 1 ton of sun dried scrap, contain- 

 ing 10 to 20 per cent, of moisture." 



" In regard to prices for the past ten years, we have sold fish scrap or 

 half dry fish, as it is called in Connecticut Valley, in car-load lots in 

 bags, free on board cars at New London or Xew Haven, as follows: 



''1869, $20 to $24 per ton; 1870, $23 to $25 per ton; 1871, $20 to $25 

 per ton ; 1872, $16 to $19 per ton ; 1873, $18 to $20 per ton ; 1874, $19 

 to $23 per ton; 1875, $15 to $17.50 per ton ; 1876, $17 to $20 per ton ; 

 1877, $14 to $17 per ton ; 1878, $17 to $18 per ton. 



"Prices in bulk at factory are usually about $3 per ton lower than at 

 New Haven, owing to cost of packages, labor, and freights. Dry 

 ground fish guano was retailed ten years ago at $55 per ton, now at 

 $40 to $42.50 ; wholesale, $5 per ton less." 



Methods of manvfacture and need of improvement. — Statements by Prof. C. 



A. Goessman. 



291. The following statements from the Third Annual Report of th^ 

 Massachusetts State Inspector of Fertilizers, Prof. Goessman, who 

 has given a great deal of attention to the subject of fish manures, are of 

 special value in this connection. Professor Goessman gives an analysis 

 of a sample of dried fish scrap obtained at the chemical works under the 

 charge of Hon. S. L. Goodale, at Booth Bay, Me., where large quanti 

 ties of fresh scraps were delivered direct from the press of an adjoining 

 fish-rendering establishment. It was deemed a particularly fair sample 

 of a well rendered and carefully-dried menhaden fish. It contained 10 

 per cent, of water, 70.75 per cent, organic matter, 18.25 per cent, ash, 

 8.46 per cent, phosphoric acid, and 8.14 per cent, nitrogen. 



"About one third of the entire phosphoric acid proved to be soluble in 

 citrate of ammonia. Ether abstracted at ordinary temperature 18 per 

 cent, more of a thick, highly-colored, oily mass. 



"The following rules of rendering the fish were stated as being cus- 

 tomary in the establishment above mentioned : the fish were boiled for 

 about one-half to three-quarters of an hor.r, by means of steam of from 

 70 to 80 pounds' pressure, in large wooden tanks with false bottoms ; and 

 subsequently, after the soup had been withdrawn, subjected to a press- 

 ure of about 115 to 120 pounds per square inch. The fish mass, in con- 

 sequence of its gelatinous condition, retains usually still from 50 to 55 

 per cent, of moisture. In a large fish-rendering estabishmeut near New 

 York City, I noticed that the boiling of the fish was continued only 25 

 minutes, with steam of 50 pounds' pressure, and the rendered fish mass 

 subsequently treated with 160 pounds' pressure per square inch. 



" The soup, which contains besides the oil more or less of the glue- 

 producing, soluble nitrogenous matter of the flesh and the bones, is at pres- 

 ent discharged after, by means of settling-tanks, the oil has been care- 



