There are some who consider iodine to be the active principle of this therapeutic agent and their preference of one kind over another is due to the greater or less quantity of that principle which may be present.
Cod-liver oil is used in medicine for all kinds of diseases, scrofulous and tuberculosis affections, softening of the bones, rheumatism, gout and affections of the nervous system.
As to the theory of the therapeutic action of this powerful medical agent it is beyond my province.
Tanners and chamois-dressers use cod-liver oil to make leather soft and bright.
Substitutes for cod-liver oil or substances which have the same medical properties, are numerous; they are taken from the cetacea, from fish, amphibia, mammals, birds, reptiles, crustacea and even from the vegetable kingdom. I will only mention the best known: such as the oil derived from the liver of the ray, from the shark and herring; whale and seal oil; milk, suet, neats-foot oil; yolks of eggs; snake-oil; oil of poppy seed, linseed, nuts and sweet almonds. I leave to the disciples of Hippocrates, both present and future, the task of deciding what amount of confidence must be given to these various substitutes for cod-liver oil and I make way for them with the pleasant satisfaction of a man who has not felt the necessity of making use either of this famous remedy or of its substitutes.
I have already stated that France derives the greater portion of the codfish which it consumes from the islands of Saint Pierre and Miquelon.
In order to understand why the French fishermen are so anxious to come to such distant waters, one must have an idea of the profits to be realized and one or two examples will suffice to show this. On the banks of Newfoundland some fishermen have been known to take from 400 to 550 cod in 10 or 11 hours. On one occasion 8 men took, in one day, 80 score on the Dogger bank.
Besides, there is another inducement. The French government which, from the very outset, has been fully alive to the importance of these fisheries, gives to each vessel a bonus in proportion to the amount of its take. These bonuses vary from 16 to 20 francs per metric quintal according to destination. Moreover, each fishing-boat gets fifty francs for every member of its crew, for fishing and curing, either on the coast of New Foundland, at St. Pierre and Miquelon or on the Grand Banks, while many vessels if they be at all fortunate may make more than one trip to Europe during the same season, as it commences in May and ends in November.
The part of the sea reserved for French fishermen is very extensive. Towards the north it stretches to within three miles from the coast of New-Foundland.