In this communication the attention of the author is chiefly directed to two subjects of inquiry:—

1st, The comparative nutritive power of fish, taking the specific gravity of their substance, and the proportion of solid matter left on thorough drying, as a measure of the same. In illustration, two tables are given, containing the results of trials on several kinds of fish and other articles of animal food; from which he deduces that the difference of nutritive power of these several articles, has commonly been overrated.