714 



THE SOUTHERN PLANTER. 



been very successful. Mr. Ruffin, who has 

 taken a very lively interest in the matter from 

 the first, informs me that he will make further 

 inquiries in relation to their effects as manures, 

 and has kindly offered to communicate to the 

 Society the results of these inquiries, as an ap- 

 pendix to this report. 



Respectfully, your obedient servant, 



WILLIAM GILHAM. 

 Va. Mil Institute, Sept. 29th, 1858. 



APPENDIX. 



The discovery made by Prof. Gilham, and 

 announced in the foregoing report, of the pres- 

 ence of considerable proportions of phosphate 

 of lime in the " olive earth," is a very inter- 

 esting fact in scientific agriculture, and likely 

 to be also of great practical value to all farmers 

 who may have access to earth of this kind, and 

 know its quality and value. The "olive earth" 

 is the usual overlying layer on the eocene marl 

 of the Pamunkey, and also of the peculiar mio- 

 cene marl of Hampstead, in Kent, described at 

 pp. 491, 2 and 3 of 5th edition of Essay on 

 Calcareous Manures ; and which marl is also 

 found at Chericoke, and at Hybla, in King 

 William — from the overlying olive earth of 

 which two farms some of the specimens were 

 obtained and analyzed. What I knew, and sup- 

 posed, of the olive earth, was stated at some 

 length in the work just named, (pp. 479, 480, 

 481,) and my reasons, formed in advance of 

 any analysis, for supposing that phosphate of 

 lime was contained therein. Prof. Gilham's 

 earlier examinations (in 1853) showed the 

 presence of a small per centage of phosphate 

 of lime in most of the specimens of olive earth 

 I had then selected for him. (See his earlier 

 communications, pp. G2 and 179, Trans. V. S. 

 A. S., 1853.) Even this was of practical im- 

 portance, in conjunction with the sulphate of 

 lime, potash and soda, which he also found. 

 But his recent analyses, cleared of the cause of 

 error, which, as Prof. Gilham states, before con- 

 cealed much the larger portion of the sub- 

 stance present, have served to show much 

 larger proportions in some of these olive earths, 

 and in most of the specimens which, at his 

 request, I had sent to him. It appears, how- 

 ever, that the proportions vary very much in 

 different specimens and places — from less than 

 1 to more than 7 per cent, of phosphate of 

 lime — and that important differences, in this 

 respect, are not only found in different remote 

 exposures and localities, and different beds, 

 but at different heights in the same bed and 

 section, and where there is no difference of ap- 

 pearance to the eye. 



Previous to the trials made of olive earth as 

 manure, by two of my neighbours, Messrs. 

 John Beale and Henry Jones, and their re- 

 markable results, (to which Prof. Gilham refers 

 as being stated to him by me, and which I hadj 



reported in the nature of " olive earth," just 

 referred to,) this earth had been deemed of no 

 value. Almost every marler in this neighbour- 

 hood had to dig through more or less of this 

 earth to uncover his marl, and with much la- 

 bour, and it was thrown aside as worthless. 

 In later years, the olive earth has been carried 

 out and spread as manure, like the marl, and 

 generally on the same surfaces. Since I learn- 

 ed the remarkable results of the more recent 

 analyses, (above stated,) I have sought to 

 learn more of the experienced practical effects. 

 But there have been no accurate experiments 

 made, of the effects, either of olive earth alone, 

 or in any certain mixtures with marl — except 

 the one I formerly saw and reported, of Mr. 

 Henry Jones. His experiment was made with 

 Dr. C. C. Cocke's olive earth, (above designat- 

 ed as Nos. i. and ii. in the present report.) 

 Mr. John Beale has made much greater use 

 from the same bed — and he only (except Mr. 

 Jones) had then used the olive earth alone, 

 without marl previously having been applied 

 on the same surface. Mr. Beale informs me 

 that he has always found great benefit from his 

 applications. He, and four others of my neigh- 

 bours, who have since used this manure large- 

 ly, but on land also marled, (and without any 

 accurate observation of the different effects,) 

 all are well satisfied with their results. But it 

 is true that there is nothing more definite than 

 mere general opinions as to the degrees of ben- 

 efit. Also, the olive earths that contain the 

 smallest proportions of phosphate of lime, 

 seem (to these loose observations) to have been 

 as satisfactory in supposed effects on the farm 

 on which they were used, as the richest in that 

 ingredient elsewhere. 



My own use of this earth, (of the Marl- 

 bourne bed,) marked 17 in Prof. Gilham's first 

 report (Trans., Vol. I., p. 69, 70,) was very 

 large — but it was applied before I knew its 

 value, on land also marled, and without the 

 care necessary to have accurate comparative 

 results. I can only say that from general ob- 

 servation of products, I believe that considera- 

 ble benefit has been produced, over and above 

 all that is due to the marl. But I made noth- 

 ing that deserves to be called a proper experi- 

 me it, and therefore have no accurate or relia- 

 ble results. 



Still, on the whole, after learning the large 

 proportion of phosphate of lime in our olive 

 earth, I am surprised and disappointed that 

 the benefit the land and crops, from this very 

 valuable and fertilizing ingredient, should not 

 have been greater and more striking, even 

 from such irregular applications. The very 

 great value of phosphate of lime as manure 

 has been well and long established. Bones, 

 which contain only about 56 per cent, of 

 phosphate of lime, have, for this ingredient, 

 been used very extensively, and with great ef- 

 fects, in England, and bought for manure at 

 three shillings sterling the bushel. The usual 



