The season runs from February to November. At the Grand Banks of New-Foundland it begins in May. When the cod is taken it is salted or dried. In the first case it is gutted, the liver and eggs removed after cutting off the head and tongue which are put to one side. It is then known as green cod-fish. It is highly important to have on board each vessel a man who is skilful in opening the fish and cutting off the heads. White cod is that which is salted but dried quickly and on which the salt leaves a kind of whitish crust. To complete the drying it is exposed to the sun, and afterwards smoked; it is then known as dry cod-fish. It is sometimes confounded under the name of stock fish (merluche), with the sea-fish prepared in the same manner on the shores of Provence. Cod fishing is carried on either on rocky shores or on sand banks where the largest fish are taken at depths varying from 25 to 50 fathoms.
It is impossible to find exactly how cod fishing originated. Some endeavor to give the credit to the Portuguese Gaspar Corterreal, at the beginning of the 16th century; but it is thought, with far more reason, that the Basque fishermen, while in pursuit of whales, discovered the grand and lesser Banks of New-Foundland a century before the expedition of Christopher Columbus. These hardy fishermen had explored the coast of Canada and assuredly knew New-Foundland, the land of the Bacalaos as they called it, before the great Genoese navigator cleaved the Caribbean sea with the prow of a European vessel. The Dutch and English appear also to have engaged in cod fishing as early as the 14th century, the latter on the coast of Iceland, and the fishermen of La Rochelle and Brittany had cast their lines in the waters of the Gulf of St. Lawrence long before Jacques-Cartier had unfurled the standard with the golden fleurs-de-lys, to the astonished gaze of the Hurons of Stadacona.
Cod may be caught in various ways, with ordinary and deep sea lines, seines and large nets. But the first of these means, while productive of excellent results, is the best as regards the future of the fisheries, and this is established by many facts. However prolific the cod might be, man's blind avidity would succeed, if not in destroying the species, at least in considerably lessening the value of the fisheries, if a wise legislation did not by far-seeing enactments oppose the insatiable cupidity of those who think only of the present. It is a fact well-known in this country that the fishermen from the United States, after having, like prodigals, wasted their own cod fisheries, would have done the same with those in Canada if they had not been prevented. How could it be otherwise, when some of the boats had from 4 to 6 deep sea lines with 1,000 hooks to each. The American fishermen have by this means destroyed several species in Canadian waters. As was stated in the famous speech delivered on the 3rd May, 1879, in the House of Commons at Ottawa, by the Honorable Mr. Pierre Fortin the member for Gaspé, the first president of this Geographical Society, and one whom I have the honor of counting among my personal friends, these interminable deep-sea lines kill off the female fish. Seining is equally prejudicial, for, with the larger fish, there are caught numbers of small fry which have to be thrown back into the sea, where their remains frequently poison the waters or supply such a quantity of food to the fish that they for a long time disdain the bait of more conscientious fishermen.
The flesh of the cod-fish is not the only portion of it which is used. Amongst other things, its liver yields the celebrated oil which is so useful to science and industry.
It is obtained chiefly from the common cod gadus morrhua of which we have spoken. In addition to Newfoundland the principal places where it is manufactured are Dieppe, Dunkirk, Ostend, England, Holland and the Loffoden Isles. The processes vary and produce oils of different qualities; they maybe reduced to two: 1. Preparing the oil by means of putrefaction and the heat of the sun or artificial heat; 2. Preparing it exclusively by means of artificial heat. In New-Foundland the livers taken from the fish are thrown into large vats in the bottom of which numerous holes are pierced and which serve to drain off the oil as well as the blood and serum into other vats which are placed beneath. The oil which rises to the surface is then collected, in large barrels.
There are five varieties of cod-liver oil: 1°. The light coloured; 2°. The brown; 3°. The black; 4°. The pale; 5°. The golden green. The first is a golden yellow with a very faint smell; it at first tastes sweet but afterwards has a sharp taste. The second is of the color of brown ochre, has a strong fishy smell similar to that of salt herring and a fishy taste. The third is of a dark brown, almost black, color with a nauseating smell, bitter and empyreumatic in taste. The fourth is yellowish with no particularly pronounced smell and taste. The fifth is transparent, golden green in color, sweet to the taste and smell. Ordinary cod-liver oil is that prepared with perfectly fresh livers with a soft, dry heat, kept free from contact with the air, in jars of earthenware or crockery. According to the chemists Delattre, Girardin and Riégel, its composition is as follows:
| Oleine | 988.700 |
| Margarine | 8.760 |
| Chlorine | 1.122 |
| Iodine | 0.327 |
| Bromine | 0.043 |
| Phosphorus | 0.203 |
| Sulphur | 0.201 |
| Phosphoric acid | 0.108 |
| Sulphuric acid | 0.236 |
| Loss | 0.300 |
| —— | |
| Total | 1,000,000 |
Cod-liver oil is the object of much adulteration. The oils, which are substituted in its stead, are generally: refined fish oil, either alone or mixed with iodine or, iodides; cod-liver oil itself mixed with ordinary fish-oil; olive oil or the oil of poppyseed and even sometimes with colza oil. Chemists have sought in vain for the proper means of discovering these various kinds of adulteration, or at least they have all arrived at different conclusions which do not give the desirable scientific certainty. The only real result that has been obtained is that the presence or absence of cod-liver oil in any given oil can be ascertained. The test employed is concentrated sulphuric acid. If a few drops are poured into a small quantity of cod-liver oil spread on a piece of glass laid upon white paper, a violet ring will form which soon becomes crimson and in a few minutes brown.