THE SOUTHERN PLANTER. 



Hanover county, and all from the same expos- 

 ed section on the Pamunky river. 



No. x.— "Olive earth," at the depth of four 

 feet below its top, contains traces only of phos- 

 phoric acid. 



No. xi. — " Olive earth," at a depth of eight 

 feet, a very little black gravel mixed with it, 

 contains 1.58 per cent, of phosphate of lime. 



No. xii. — " Olive earth," at a depth of ten 

 feet, six inches above gravel bed No. xiii., con- 

 tains 3.23 per cent, of the phosphate. 



No. xiii. — "Olive earth," containing black 

 gravel — stratum from three to five inches 

 thick. This, after the gravel was crushed, and 

 thoroughly mixed with the earth, gave me 

 24 per cent, of phosphate of lime ! 



No. xiv. — Marl, two and a half feet below 

 No. xiii., contains more or less black gravel. 

 The gravel was crushed and mixed with the 

 marl ; the mixture, on analysis, gave 7.89 per 

 cent, of phosphate of lime. 



No. xv., xvi. and xvii. — " Olive earths," from 

 the same section, on the farm of W. A. Brax- 

 ton, Hybla, King William county. 



No. xv. contains 1.37 per cent., No. xvi., 

 1.58 per cent., and No. xvii. 0.93 per cent, of 

 the phosphate. 



Nos. xviii. and xix. — "Olive earths," from 

 Chericoke, King William county, selected by 

 Dr. Tomlin Braxton. 



No. xviii. is ten or twelve feet thick, over- 

 laid by nine or ten feet of earth, and contains 

 7.41 per cent, of phosphate of lime. 



No. xix., about four feet in thickness, and 

 overlaid by four feet of earth, contains 2.54 

 per cent. 



No. xx. — " Olive earth," from Bassetterre, 

 King William county, selected by G. W. Bas- 

 sett, contains 3.77 per cent, of phosphate of 

 lime. 



No. xxi. — " Olive earth," from same locali- 

 ty, contains 3.G4 per cent. 



No. xxii. — " Olive earth," from G. W. Bas- 

 sett's, Farmington, Hanover county, contains 

 6.38 per cent. 



I may remark that the "olive earth," No. 

 xiii., and marl, No. xiv., owe their large per 

 centage of phosphate of lime to the presence 

 of black gravel. Mr. Ruffm informs me that 

 numerous beds of Eocene marl contain, in thin 

 bands, or layers of the marl, more or less of 

 this gravel, but always in small quantities. In 

 all such cases, we should expect the marls to 

 contain very considerable amounts of phos- 

 i phates of lime, in proportion to the quantity 

 * a TT S * me "5 N ?' 7h Rnd V 1 '' but at of the black gravel. 



the depth of nine and a half feet below top of TT ...7 , , .. c , 



blue clay, (No. 16, pages 69, 70;) this con- • Up to witlnn a very short time of my mak- 

 taincTdl ^vpont i u u J ing my first examination of the " olive earths," 



tains i .41 pei cent, of the phosphate. | ^ ^ ^ ^ t rdB & as worthless. Mr. 



uVat • ax P S taken fr0m " olive 'Ruffin, however, having heard that a very sue- 

 earth No. iv. After being crushed and thor- C essful experiment had been made by the use 

 oughly mixed they were found to contain 56 j f some, called my attention to them, and sent 

 per cent of phosphate of lime ! | me some gara p]es for analysis. Since the pub- 



Nos. x., xi., xii., xiii. and xiv. were procured lieation of my report, various trials of these 

 by Mr. Ruffm from T. G. Turner, Springfield, earths have been made, and some of them have 



merous smooth black pebbles, some of which 

 were casts of shells, &c, he remarked that 

 wherever they had been applied, they seemed 

 to have produced good effect, and suggested 

 the idea that perhaps they were rich in phos- 

 phate of lime. Their appearance, however, led 

 me to think that they were nothing but impure 

 carbonate of lime, and when a strong acid was 

 dropped upon them, the effervescence which 

 took place was so marked, that I was confirm- 

 ed in my belief, and thought that I should be 

 wasting my time to subject them to analysis. 

 After completing the analysis of the " olive 

 earths," I had occasion to throw a few of these 

 pebbles into muriatic acid ; finding that com- 

 plete solution soon took place, and that the ef- 

 fervescence was not so vigorous as I bad a 

 right to expect on the assumption that the 

 whole, or nearly the whole, was carbonate of 

 lime, I determined to subject them to analysis 

 for the phosphates. I find them all to contain 

 the phosphate of lime in large proportions. 



The numbers which follow are simply given 

 for convenience in reference. • 



No i. — " Olive earth," from Retreat, (from 

 Dr. C. C. Cocke's.) reported upon, and referred 

 to at No. 19 of my first report, (page 69.) This 

 specimen contains 6.86 per cent, of phosphate 

 of lime. 



No. ii. — " Olive earth," same locality, and 

 reported upon in former report as No. 18, (page 

 09.) This contains 3.92 per cent, of the phos- 

 phate. 



No. iii. — " Olive earth," Marlbourne Farm, 

 (No. 17, on pages 69, 70, first report,) from 

 eight and a half to nine feet below top of blue 

 clay, (No. 16,) contains 5.012 per cent. 



No. iv. — " Olive earth" containing black 

 gravel, — Marlbourne, (No. 17, pages 69, 70,) — 

 contains, after the removal of the gravel, 5.15 

 per cent, of phosphate of lime. 



No. v. — Blue clay overlying the " olive 

 earth," Marlbourne/ (No. 16, page 69,) ob- 

 tained by Mr. Ruffm by boring. The first five 

 feet contained only traces of phosphate of lime; 

 the sixth foot contained 4.80 per cent. 



No. vi. — " Olive earth," Marlbourne Farm, 

 (No. 17, pages 69, 70,) also obtained by boring, 

 — specimen at the depth of eight feet below 

 top of blue clay, (No. 16. pages 69 70,) con- 

 tained 5.97 per cent. 



No. vii — Same as No. vi., (No. 16, pages 

 69, 70,) but at the depth of nine feet below 

 top of blue clay, 16,) contains 7.27 per cent. 



