Cuvier tells us that “almost all the parts of the cod are adapted for the nourishment of man and animals, or for some other purposes of domestic economy. The tongue, for instance, whether fresh or salted, is a great delicacy; the gills are carefully preserved, to be employed as baits in fishing; the liver, which is large and good for eating, also furnishes an enormous quantity of oil, which is an excellent substitute for that of the whale, and applicable to all the same purposes; the swimming-bladder furnishes an isinglass not inferior to that yielded by the sturgeon; the head, in the places where the cod is taken, supplies the fishermen and their families with food. The Norwegians give it with marine plants to their cows, for the purpose of producing a greater proportion of milk. The vertebræ, the ribs, and the bones in general, are given to their cattle by the Icelanders, and by the Kamtschatkadales to their dogs. These same parts, properly dried, are also employed as fuel in the desolate steppes of the shores of the Icy Sea. Even their intestines and their eggs contribute to the luxury of the table.” I may just mention another most useful product of the codfish. Cod-liver oil is now well known in _materia medica_ under the name of _oleum jecoris aselli_. The best is made without boiling, by applying to the livers a slight degree of heat, straining through thin flannel or similar texture. When carefully prepared, it is quite pure, nearly inodorous, and of a crystalline transparency. The specific gravity at temperature 64° is about ·920°. It seems to have been first used medicinally by Dr. Percival in 1782 for the cure of chronic rheumatism; afterwards by Dr. Bardsly in 1807. It has now become a popular remedy in all the slow-wasting diseases, particularly in scrofulous affections of the joints and bones, and in consumption of the lungs. The result of an extended trial of this medicine in the hospital at London for the treatment of consumptive patients shows that about 70 per cent gain strength and weight, and improve in health, while taking the cod-liver oil; and this good effect with a great many is permanent. Skate-liver oil is also coming into use for medicinal purposes, and I have no doubt that the oil obtained from some of our other fishes will also be found useful in a medicinal point of view.