ess 



FARMERS' REGISTER 



[No. 11 



tions — whether the term was limited to the pure chem- 

 ical earth lime alone, or was made to embrace every 

 combination of lime whatever. Either of these ap- 

 plications would have been far more regular in ap- 

 pearance, and more suited to scientific arrangement. 



The defence for the course adopted as to this term, 

 was given in a note in the Appendix to the Essay; 

 Which, as it has not been seen by many who will 

 read these letters, will be copied here. The passage 

 presents the views which then induced the decision, 

 and which still remain unchanged. 



"The definition of "calcareous earth," which con- 

 fines that term to the carbonate of lime, is certainly 

 liable to objections, but less so than any other mode 

 of arrangement. It may at first seem absurd to con- 

 sider as one of the three principal earths which com- 

 pose soils, one only of the many combinations of lime, 

 rather than either pure lime alone, or lime in all its 

 combinations. One or the other of these significations 

 is adopted by the highest authorities, when the calca- 

 reous ingredients of soils are described—and in either 

 sense, the use of this term is more conformable with 

 scientific arrangement, than mine. Yet much incon- 

 venience is caused by thus applying the term calca- 

 reous earth. If applied to lime, it is to a substance 

 which is never found existing naturally, and which will 

 always be considered by most persons as the product 

 of the artificial process of calcination, and as having 

 no more part in the composition of natural soils, than 

 the manures obtained from oil-cake, or pounded bones. 

 It is equally improper to include underthe same gene- 

 ral term all the combinations of lime with the fifty or 

 sixty various acids. Two of these, the sulphate, and 

 phosphate of lime, are known as valuable manures; 

 but they exist naturally in soils in such minute quanti- 

 ties, and so rarely, as not to deserve to be considered 

 as important ingredients. A subsequent part of this 

 essay will show why the oxalate of lime is also sup- 

 posed to be highly valuable as a manure, and far more 

 abundant. Many other salts of lime are known to 

 chemists: but their several qualities, as affecting soils, 

 are entirely unknown— and their quantities are too 

 small, and their presence too rare, to require considera- 

 tion. II ail the numerous different combinations of 

 lime, having perhaps as many various and unknown 

 properties, had not been excluded by my definition of 

 calcareous earth, continual exceptions would have been 

 necessary, to avoid stating what was not meant. The 

 carbonate of lime, to which I have confined that term, 

 though only one of many existing combinations, yet 

 in quantity and in importance, as an ingredient of soils, 

 as well as a part of the known portion of the globe, 

 very far exceeds all the others. 



"But even if calcareous earth, as defined and lim- 

 ited, is admitted to be the substance which it is proper 

 to consider as one of the three earths of agriculture, 

 still there are objections to its name, which I would 

 gladly avoid. However strictly defined, many readers 

 will attach to terms such meanings as they had pre- 

 viously understood: and the word calcareous has been 

 so loosely, and so differently applied in common lan- 

 guage, and in agriculture, that much confusion may 

 attend its use. Any thing "partaking of the nature 

 of lime" ia "calcareous," according to Walker's Dic- 

 tionary: Lord Karnes limits the term to pure lime* — 

 Davyf and Sinclair,| include under Lt pure lime and 

 all its combinations — and Kirwan,|| Roziei%§ an^r 1 

 Young,1T whose example I have followed, confine the 



•Gentleman Farmer, page 2H, (2d Edin. Ed.) 

 fAgr. Clscm. page 223, (Phil. Lid. of 1821.) 



/ irricultiire, page 134, (Hartford Ed. 18 

 pKirwan on Manures, Chap. 1. 

 S"3Vret" — Cours Cornplet d'Agriculture Prathiu 

 tYoung'i Essay on Manures, Chap. 3. 



name calcareous earth to the carbonate of lime. Nor 

 can any other term be substituted without producing 

 other difficulties. Carbonate of lime would be precise, 

 and it means exactly the same chemical substance: but 

 there are insuperable objections to the frequent use 

 of chemical names in a work addressed to ordinary 

 readers. Chalk, or shells, or mild lime, (or what had 

 been quicklime, but which from exposure to the air, 

 las again become carbonated,) all these are the same 

 chemical substance — but none of these names would 

 serve, because each would be supposed to mean such 

 certain form or appearance of calcareous earth, as 

 they usually express. If I could hope to revive an 

 obsolete term, and with some modification establish its 

 use for this purpose, I would call this earth calx — and 

 from it derive calxing, to signify the application of 

 calcareous earth, in any form, as manure. A general 

 and definite term for this operation is much wanting. 

 Liming, marling, applying drawn ashes, or the rubbish 

 of old buildings, chalk, or limestone gravel — all these 

 operations are in part, and some of them entirely, that 

 manuring that I would thus call calxing. But because 

 their names are different, so are their effects generally 

 considered — not only in those respects where differ- 

 ences really exist, but in those where they are precisely 

 alike." 





EXTRACTS FROM THE REPORT OF THE GE- 

 OLOGICAL RECn.MVOISSAKCE OF THE STATE 

 OF VIRGINIA, MADE UNDER THE APPOINT- 

 MENT OF THE BOARD OF PUBLIC WORKS. 



By William B Rogers, Professor of Natural Phi- 

 losophy in the University of Virginia. 



[Continued from p. 634 Vol. III.] 



Of the Green Sand, Sulphate of Iron, Sulphur, 

 and other matters associated xoith the marl 

 beds. 



Green Sand. — As already intimated, this sub- 

 stance is frequently ibund disseminated in the 

 marl, and also in the overlying stratum of clay or 

 sand. From the remarkable effects of compara- 

 tively small quantities of this material when ap- 

 plied to land, there can be no doubt that many of 

 the marls of lower Virginia owe some of their 

 value to its presence. Supposing only as much 

 as 10 per cent, of this substance in a marl, and 

 this is far below the amount which I have ascer- 

 tained to exist in many localities, '100 loads of 

 mail would correspond to ten of the green sand, 

 an amount which in New Jersey has often been 

 found productive of striking benefit. Several of 

 the most efficient marls which I have examined, 

 were more remarkable for the large proportion of 

 this substaajSe contained in them than for their 

 richness in calcareous matter. Jn many marl pits 

 which jr-have visited, the impressions of the pick 

 and si ade were streaked with green marks, which 

 upon 'inspection were found to result from the 

 bruised granules of this matter. In such cases, 

 i here can he no doubt of the existence in the marl 

 of an amount of green sand capable of affording 

 material aid to the growing vegetable. In the 

 layer immediately above the marl also, it some- 

 times exists in considerable quantity — and hence 

 instead of rejecting this overlying mass, in many 

 cases it would be decidedly better to carry it out 

 upon the land along with the calcareous matter. 

 The experience of many farmers has already 

 shown the propriety of this plan, and some even 

 entertain the opinion that this upper layer, where 



