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XXVII. — Oil the Application of Geology to ylyrinilture. — By 

 Sir John V. B. Johnstone^, Bart.^ F.G.S. — Communicated 

 by Philip Pusey, Esq._, M.P. 



My dear Puse\% 

 In compliance with your request that I woukl furnish you with 

 the particulars of the geological map and survey of my Yorkshire 

 estate, made several years ago by Dr. Smith (whose recent loss 

 we have to deplore), with the view of enabling you to ascertain 

 how far the facts and practical results thus obtained are likely to 

 elucidate the necessary connexion between geology and agricul- 

 ture, I have much pleasure in placing the following observations 

 in your hands, begging you will make any use you please of them 

 in illustrating an inquiry of so useful and interesting a nature. 



In the year 1828, having observed great variations in the soils 

 upon my estate, not only on the sides of the hills, which might 

 be expected, but also in the fields upon the table-land forming 

 the summits of these hills, and which, from being flat, or rather 

 declining to the south Avitli a gradual and easy slope, rendered the 

 variation more difficult to explain, I mentioned the subject to Dr. 

 Smith, who was then lecturing at Scarborough, and surveying the 

 surrounding district, with the view of proving the identity of the 

 Hackness strata with those near Oxford. He at once offered a 

 solution of my difficulty by a reference to geology; and, having 

 gone over minutely the fields in question, with a reduced map of 

 my estate in his hands, he marked upon it, in different colours, 

 the ranges of these strata, as they exhibited themselves in succes- 

 sion upon the surface, forming themselves into zones or breadths 

 of one, two, or more fields together, according as the particular 

 stratum which came to the surface was more or less horizontal^ or 

 more or less thick. 



The result thus obtained clearly demonstrated that the value 

 of each field, and the mode of cultivation already adopted (with 

 the exception of the use of lime, which had been too frequently 

 and too indiscriminately applied to the entire estate), corresponded 

 to the variations of the strata, and were limited by the areas which 

 these occupied on the surface ; thus sho-VAing that (though the 

 results had been arrived at by the farmers through a different 

 process, viz., trial and error) the geological character of a country, 

 when accurately understood, pointed out at once the natural value 

 of the land, and the system of cultivation best adapted to it. For 

 instance, on the highest range of my hills, a few fields, without any 

 apparent reason, have been universally productive in all seasons, 

 more so than the fields adjoining them on a lower level, and which 

 appeared nearly of the same quality. The fossils, and other 

 marks well understood by Dr. Smith, proved them to consist of 



