The " basking shark " is found all along the Norwegian coast, from Ryvarden (59° 31' N. lat.) to Finmark. Its pursuit was long followed with such activity and success as to afford the staple support of those engaged in it, but of late years decreasing numbers have much reduced its importance. Its chase resembles that of the whale rather than of other kinds of shark, as it cannot be baited nor enticed. Towards the conclusion of the dog-days, when the sea and the air are at their highest temperature, this fish makes its appearance on the coast ; it lies perfectly still near the surface of the water, apparently basking in the sun, and follows leisurely after the boats which are in quest of it. It is thus struck by harpoons, such as are used for taking sturgeon. In size and condition it varies much ; the prevailing length is 30-35 ft., increasing occasionally to 40 ft. The size of the liver depends mostly on the condition of the fish ; the usual quantity of liver taken from a fish is 4-7 barrels, occasionally 10-16, and in very rare iustancee 24 ; 6 barrels of good liver should yield 5 barrels (of 30 gal.) of oil. The same fish is found in Indian waters, and is there called mhor. It is harpooned in great numbers by the Kurracliee fishermen, one estimate stating the annual catch at 40,000. The size here varies from 40 to 60 ft. in length, and the usual yield from one liver is 8 barrels of oil, of very low ap. gr.
The pinked dog-fish, which was formerly very abundant along the whole coast from Gothenburg, is now pursued during the entire summer, from the Naze to the North Cape, in the Norwegian fjords as well as along the coast. About midsummer it swims near the surface, and is taken either by nets or lines. The liver is exceedingly rich in very fine oil.
The kulp or hoastorsh is met with in all the deep fjords along the Norwegian coast, where it does much mischief by nibbling off the baits from the deep-sea cod-lines. It is taken in numbers at a time, by lines with 10-12 hooks baited with tainted fish, in 60-100 fathom water. It travels in shoals, and feeds at night. Its liver is unusually rich, and yields a superior oil.
Sharks are caught in great numbers on the shores of New Zealand, during November-January, by the natives, who use them for food. A premium for the capture of sharks offered by the Victorian Government has promoted this branch of fishing among the sailors of Hobson's Bay, and very large numbers are now taken. They are also very common in Sydney Harbour, New South Wales.
Shark-oil is largely used in tanneries. It is also extensively passed off surreptitiously as cod liver-oil and is probably but little less efficacious ; the oil and liver are both esteemed as food hX the Icelanders.
term "sod "-oil is applied to the oil which has been fulled into skins during the operation of tanning, and has been subsequently washed out with soda. English sod-oil comes
chiefly from deer- and sheep-skins, and is largely adulterated with gelatine from green sheep skins. The purest and best sod-oil is from France, where olive-oil is employed in the tanning ; the next is English, where cod-oil has been used ; then comes American, where the currying has been done with " fish-oil " (menhaden-oil). This last now fetches the highest price. Sod-oils are much esteemed for lubricating delicate watches, &c.
Spermaceti or (Fa., Spermaceti, Blanc de Balcine ; GER., Spermaceti, Walrath).
—"Spermaceti " is chiefly the solid wax-like portion of the sperm-oil, or so-called:," head-matter," found in the head of the " sperm-whale " or cachalot (Physeter macrocephalus), an inhabitant of the Pacific and Indian Oceans. On the right aide of the nose, an& upper portion of head of this species, is a triangular-shaped cavity, termed the "case," enveloped by an enormous mass of sinewy gristle called "white horse," which resists even a sharp axe. The case is filled with liquid "head matter," consisting of spermaceti and oil ; the whalers make an opening into the case, and remove the contents by a bucket, as many as 45 barrels being occasionally filled. This matter is carefully boiled alone, and placed iu separate casks, and is commonly known as head-matter. It is of a yellow colour, and its consistence varies with the temperature. It undergoes a purification for the purpose of candle-manufacture, in which it is employed (see Candles, p. 589). The refined article is transparent, smooth, brittle, insipid, inodorous, and very difficultly saponifiable ; its sp. gr. is 0.943 at 15° (59° F.) ; it is fusible at 45° (113° F.) ; it is insoluble in water ; 100 parts of alcohol of 0.821 sp. gr. dissolve 3i parts of spermaceti, hut deposit about is on cooling ; it is also soluble in both fatty and volatile oils. It is said to be adulterated commonly with fatty matters, such as tallow, margaric acid, &c. Such falsifications are easily discovered by the saponification of the mass, and by the reduction of the fusing-point.
Similar products are obtained in lesser quantities from the head-cavity of P. Tursio and Delphinus edentulus, from the bladder of Balana rostrata, and from the oil of Delphinus globiceps.
The Tasmanian whale-fishery produced 558 tuns of sperm-oil in 1873, and 342 in 1874. The exports in 1876 were 513 tuns, value 45,2481.; and in 1878, 279 tuns, value 17,577/. The pro duction in 1869 was 643 tuns. The exports of sperm-oil from New York in 1878 were 911,975 gal. to Great Britain, 49 gal. to N. Europe, and 579 gal. to S. America, E. and W. Indies, &c., total 912,603 gal. ; in 1879, they were 1,089,137 gal. The production of spermaceti in the American whale-fisheries was 1,300,959 gal. in 1878, and 1,285,454 gal. in 1879.