20 THE COAST REGION. 



work on cotton culture, publislicd by Orange Judd & Co., New York. It 

 is stated tliere (page 129) tliat a chemical analysis discloses the fact that 

 the soil on an acre of sea island cotton land, taken to the depth of one 

 foot, contains only fifteen pounds of phosphoric acid and twenty pounds 

 of potash. By the above analyses, however, we find an average of more 

 than one-tenth of one per'ccnt. of phosphoric acid, and one-sixteenth of 

 one per cent, of potash'. Allowing a cubic foot of earth to weigh one liun- 

 dred pounds, we w'ould have on an acre to the depth of one foot four mil- 

 lion, three hundred and fifty-six thousand pounds, of which one-tenth pf 

 one per cent, would be four thousand, three hundred and fifty-six pounds, 

 showing nearly two long tons of phosphoric acid instead of fifteen pounds 

 to the acre. The potash, by the same calculation, would amount to five 

 thousand and fifty pounds instead of twenty pounds to the acre. Thus, in 

 the place of being barren for lack of these ingredients, each acre of the sea 

 islands possess an amount which, if rendered available to plant growth, 

 w^ould suffice for the production of over eight million, six hundred and 

 eighty thousand pounds of lint cotton, as they do not, by Jackson's and Shep- 

 ard's analyses, constitute the one-twentieth of one per cent, of cotton fibre. 

 Basides, the salt marsh materials for maintaining and developing the fer- 

 tility of the soil abound throughout the coast region. There are numer- 

 ous deposits of post pleiocene marl on the islands, as at Daton's swamp, 

 Johnson's island, Stono creek, Edisto island, James Seabrook's island, 

 Distant island, near Beaufort, and elsewhere. The banks of " raccoon 

 oyster " .shells, peculiar to this latitude, are found in abundance on 

 this coast and furnish excellent and easily accessible stores of lime. 

 These shells are also used for concrete for walls, known as tabby 

 work. The walls of forts several centuries old attesting its dura- 

 bility. Roads and streets are also made smooth and hard by their use. 

 Here, also, in the Stono, Edisto, Coosaw, Bull, Morgan, Johnson's, Beau- 

 fort and Broad rivers, and in other creeks and marshes, is found, and 

 largely exported as a fertilizer to foreign lands, the phosphate rock. Ex- 

 periments have also demonstrated that the fish, so numerous in these 

 waters, may be caught and used for manures. 



CLIMATE. 



Notwithstanding their proximity to the mainland, the sea islands 

 enjoy in a high degree the equable climate peculiar to islands generally. 

 The extremes of temperature are, as might be expected, greatest in the 

 direction of low temperature, and the cold, which is sometimes injurious 

 to the orange and olive trees, destroys, also, the germs of many insects, as 

 of the cotton caterpillar, inimical to vegetation; and of more importance 



