ERRORS OP SINCLAIR. 389 



titles as merely to make its presence evident to the analyzer, in a 

 soil before entirely deficient. 



30. The next following quotation offers the most remarkable 

 evidence of erroneous opinions of the chemical action of different 

 mineral manures, uttered by a modern author of the highest repu- 

 tation as a scientific agriculturist. Sir John Sinclair was a volu- 

 minous and able writer. Presiding over the British Board of Agri- 

 culture, he mainly directed its operations, and of course was fami- 

 liar with all the lights of British agriculture brought together in 

 the published reports of all the agricultural surveys of the counties 

 of Great Britain and Ireland. Moreover, the professed object of 

 his latest work, the " Code of Agriculture" was to present a 

 digest of all the valuable facts and instructions elicited by all those 

 voluminous surveys and reports, and tested and established by judi- 

 cious and authoritative approval. Yet in the 5th London edition 

 of his " Code of Agriculture," as late as 1832, and with numerous 

 recent additions and improvements to the work, the following pas- 

 sages stand in an article with the title below : 



"On bones as a manure, and on the use of shells, shell-marl and coral 

 for the same beneficial purposes." 



"Were the advantages of the discovery restricted to the use of bones 



alone, as they might possibly be exhausted, or raised in price, it would be 

 less important ; but fortunately the shells of oysters, and other fish, are 

 found to be equally effectual. Shell marl also, which abounds in many parts 

 of the kingdom, may be applied to similar purposes ; and coral, the banks 

 of which are abundant even on our own coasts, is found to be equally use- 

 ful. In short, it is impossible to foresee what may be the ultimate results 

 of this neiv source of improvement, for by a small quantity [25 bushels to 

 the acre, as elsewhere directed] of pounded bones or shells, great crops of 

 turnips may be raised ; and with the manure which these turnips produce, 

 abundant crops of corn may be obtained even on the poorest soils, with the 

 aid of a judicious rotation." (Code of Agr., 5th Lon. ed. p. 141, Appendix.) 

 * * * <4^ s bones are likely to become a scarce article, it is a most fortu- 

 nate circumstance that the shells of oysters and other shell-fish, when properly 

 reduced in size, have been found equally useful as a manure. Their utility 

 would be much increased if they were sprinkled with sulphuric acid, by 

 the addition of which they would be converted into gypsum." (p. 146.) 



Thus, the distinguished " author, as late as 1832, asserts that 

 substances whose manuring principles are almost exclusively com- 

 posed of carbonate of lime, will serve to substitute, and act alike 

 and as effectually, as those which are almost exclusively composed 

 of phosphate of lime (and of fatty and gelatinous animal matter, 

 if these remain) ; and then recommends, as still better, the con- 

 verting the carbonate to the sulphate of lime or gypsum ! This 

 last-named manure, moreover, has not been found of benefit but in 

 few cases in England. It is unnecessary to expose, by further com- 

 ments, this confounding of the action and effects of three manur- 

 ing substances, all valuable in their places, yet each very different in 

 action from the others. 

 33* 



