272 KEPORT OB^ COMMISSIONER OP FISH AND FISHERIES. 



anniiai production is said to be upward of 10,000 tons of i)repared 

 scrap, about 20,000,000 cod heads being utilized for tlie purpose. 



According to a report made by Consul-General Crowe, of the Brit- 

 ish service, the lieads and bones are first partly dried in the open air 

 and then cut into small pieces and thoroughly dried in a kiln. When 

 all but 12 or 15 per cent of moisture has been driven off, the materials 

 are crushed and then ground between millstones to the fineness of 

 corn meal. The heads and bones are crushed separatel}', but are 

 mixed together before the grinding process, the usual proportion of 

 the mixture being one part of the backbones to five parts of the heads. 

 Chemical analyses indicate an average content of water lo per cent; 

 organic substances 49.3 per cent, of which 8 per cent is nitrogen and 

 7.6 per cent ammonia; and inorganic substances 37.7 per cent, of 

 which 14.9 per cent is phosphoric acid. 



In utilizing whales at the Norwegian stations established in con- 

 nection with the taking of these cetaceans, the fiesh and bones are 

 commonly prepared as fertilizer after the extraction of the oil. The 

 blubber and the fat-lean are first removed from the fiesh for oil-ren- 

 dering, and then the fiesh is cut into strips or minced in a machine 

 and boiled with steam under pressure. As described by Michael 

 Winnem, in Chemische Revue, the receptacles for boiling the fiesh are 

 horizontal iron cylinders provided with close-fitting openings. They 

 are also provided with two outlet pipes, one at the very bottom, for 

 removing the water, and the other about 4 inches higher uj), for draw- 

 ing off the oil. The fiesh is spread on three superimposed perforated 

 trays or false bottoms, and subjected within the cylinder to steam at 

 a pressure of 40 or 50 pounds to the square inch for ten or twelve 

 hours. At the end of that period the fiesh is removed and placed in 

 drying ovens. These are built of brick, 20 to 25 feet high, and fitted 

 with internal sheet-metal trays, which are mounted alternately on the 

 sides of the oven and on a central revolving shaft. The latter carries 

 a number of slanting scrapers which revolve once in 5 minutes and 

 slowly force the flesh from one tray to the next lower ones in suc- 

 cession. The descending fiesh is dried by the heated air from a coke 

 fire, which enters the oven at the top and passes out through an 

 opening at the bottom. 



The process is somewhat slow, the output during twenty-four hours 

 not exceeding 2 tons for each oven. If desired, the fertilizer may be 

 ground in a mill. The bones are broken and treated in much the 

 same manner as the fiesh. After boiling they are crushed in a dis- 

 integrator, ground in a bone-mill, and mixed with the flesh scrap. An 

 analysis, made by Krocker, of Norwegian whale fei'tilizer indicated 

 7.63 per cent of nitrogen, 13.45 per cent of phosphoric acid, 16.49 per 

 cent of lime, and 0.15 per cent of magnesia in a sample containing 

 5.35 per cent of moisture. The market price is about £6 per ton. In 

 the bottle-nose fishery the oil is commonly extracted at sea, as in case 

 of the American whale fishery, and coiiseciuently it is not practicable 

 to utilize the fiesh and bones as fertilizer, 



