1277. The different species of corals, corallines, and sponges must be considered as substances of animal origin. From the analysis of Hatchett, it appears that all these substances contain considerable quantities of a matter analogous to coagulated albumen; the sponges afford likewise gelatine. According to Merat Guillot, white coral contains equal parts of animal matter and carbonate of lime; red coral 46.5 of animal matter, and 53.5 of carbonate of lime; articulated coralline 51 of animal matter, and 49 of carbonate of lime. These substances are never used as manure in this country, except in cases when they are accidentally mixed with sea-weed; but it is probable that the corallines might be advantageously employed, as they are found in considerable quantity on the rocks, and bottoms of the rocky pools on many parts of our coast, where the land gradually declines towards the sea; and they might be detached by hoes, and collected without much trouble. On many parts of the Scottish coast, banks of shells have been deposited by the sea, and are applied with great advantage, both as a substitute for lime and in improving the mechanical texture of the clay soils within their reach. The shell sand so largely employed in Cornwall and elsewhere as manure, consists entirely of the fragments of marine shells.
