and Professor F. S. Holmes, of the Charleston college-have so systematically explored and studied these beds that, previous to the year 1850, they were as well and widely known geologically and paleontologically as any other equally extensive in the world.

The calcareous marls of South Carolina have been closely studied, classified, and analyzed, and their value as marls, containing a small percentage of phosphate of lime, has been known for 20 years; but there is another bed, not of marl, but adjacent to these, equally well known and described, the composition of which has, until lately, been unknown and misunderstood.

Reference to the Geology of South Carolina, by Professor M. Tuomey, published in 1848, will show all that was known of them up to the year 1867, viz:

1st. That the calcareous beds of this section had been carefully studied, classified, and analyzed, and were known to contain from 50 to 85 per cent. of carbonate of lime, and from 2 to 9.20 per cent. of phosphate of lime.

2d. That the marlstones, nodules, or conglomerates, (constituting a bed which overlies the newer eocene marls,) bedded in the clay, were universally considered as silicified, having lost all or most of their lime, which rarely exceeded six per cent.—(Tuomey's Geology of South Carolina, p. 165.)

3d. That the fossil bones, marine and terrestrial, were also considered petrified or silicified.

See, also, the magnificent work on the "Post Pliocene Fossils of South Carolina," by Professor F. S. Holmes, (1859), Introduction, p. ii.

These are the published records; but Professor Holmes has informed Dr. Pratt that Professor Tuomey made a crude analysis of these nodules some years ago, and he thought the estimate was fifteen to sixteen per cent. of phosphate of lime, but not enough to counterbalance the carbonate of lime, iron, and sand which they also contained, and it was considered unavailable for agricultural purposes.

During the late war, while in charge of the chemical department of the C. S. Nitre and Mining Bureau, and engaged in inspecting the saltpetre beds of Charleston and Ashley river, which were constructed under the charge of Prof. F. S. Holmes, Dr. Pratt's attention was repeatedly directed by Prof. Holmes to the remarkable accumulation of fossil bones in a bed long since described and known as the "Fish Bed of the Charleston Basin," and also to the existence of from two to nine per cent. of phosphate of lime in the heavy marls below, as indicated by the analysis of Prof. C. U. Shepard, published in the Geology of South Carolina in 1848. Knowing that the marls of Georgia were comparatively poor in that ingredient, rarely exceeding three per cent., the contrast was too striking to escape notice; and the doctor took various samples to Augusta, Georgia, for examination, but more urgent matters at that time prevented the analysis, and the fact was almost forgotten.

Later, in May, 1867, Dr. Pratt was fortunate enough to discover that a bed outcropping within ten miles of Charleston contained as large a percentage of phosphate of lime as any of the phosphatic guanos imported from the tropical islands, and used in this country and abroad, for the manufacture of fertilizers.

This bed has been long known in the history of the geology of South Carolina as the "Fish Bed of the Charleston Basin," on account of the abundant remains of the marine animals found in it, Professor Holmes, of the College of Charleston, having in his cabinet not less than 60,000 specimens of sharks' teeth alone, some of them of enormous size, weighing from two to two and a half pounds each! The bed outcrops on the banks of the Ashley, Cooper, Stono, Edisto, Ashepoo, and Combahee rivers, but is developed most heavily and richly on the former, and has been found as far inland as 40 or 50 miles.

Near the Ashley river it paves the public highway for miles; it seriously impedes and obstructs the cultivation of the lands, affording scarcely soil enough to "hill-up the cotton rows," and the phosphates have been for years past thrown into piles on the lawns, or into causeways over ravines, to get them out of the reach of the ploughs; it underlies many square miles of surface continuously, at a depth ranging from six inches to twelve or more feet, and exists in such quantities that in some localities from 500 to 1,000 tons or more underlie each acre. In fact, it seems that there are no rocks in this section which are not phosphates!

Chemical analyses made by Dr. Pratt, in the laboratory of Dr. Ravenel, showed that samples from different localities contain from 34 to 55 and 67 per cent. of phosphate of lime. A company was soon after organized for thoroughly working this invaluable deposit, and South Carolina has now become the exporter rather than the importer of fertilizers.

6 c

APPENDIX D.

TABLE I.-Statistics of British cotton trade and manufactures, &c.—Continued.

TABLE I.-Statistics of British cotton trade and manufactures, &c.-Continued.