TEANSACTIONS OF SECTION B. 553 



and pure soil gave better results than the pure soil, derogates little, if at all, from 

 the evidence of impro'\ement given by magnesia. 



Again, Morton in his ' Encyclopaedia of Agriculture,' in opposing the erroneous 

 opinions current against the use of magnesian lime, mentions that ' In the neigh- 

 bourhood of CasteUamonte and Baldissiro, the most luxuriant vegetation is met 

 ■with on a soil which contains a very large quantity of magnesia, and in our own 

 coimtry many very fertile soils are fomid in the New Red Sandstone formation, 

 which likewise is rich in magnesia.' 



John Donaldson, the author of a ' Treatise on Manures,' having been engaged 

 in the cultivation of laud in the immediate neighbourhood of Breedon Magnesian 

 Rock in Leicestershire, says : — ' I had occasion to use considerable quantities of lime, 

 and consequently had a fair opportunity of proving the quality of that rock for 

 agricultural purposes.' On two fields (the farm he tells us had been most miserably 

 scourged and impoverished by the preceding tenants) he spread the magnesian lime 

 at the rate of 200 bushels an acre, and in another field ' a double allowance of lime, 

 or 400 bushels per acre .... which, being both a large quantity and in a caustic 

 state, would test the supposed noxious quality of the lime. In every case the green 

 crops were good ; . . . one field was sown with barley, which yielded a most 

 beautiful crop of 7-k quarters per acre, and the other produced 5 quarters of wheat, 

 both very great crops when the exhausted state of the land was considered. 



When the wheat braided in November, the space which had got 400 bushels 

 to an acre immediately showed a great superiority, which continued to the day of 

 reaping, being much thicker on the groimd, of a darker colour throughout the 

 winter, and afforded more produce as the shocks were thicker on the ground, and 

 discernible on the first view of the field. The succeeding crop of hay on that space 

 showed an equal superiority, and for several years in succession. 



' The same lime was used in the same quantity, of 200 bushels to an acre, and 

 with the same beneficial results, without a single exception. On the headland where 

 the lime lay, and where any damage might have been expected, there grew a very 

 close and heavy crop of beet, with roots not equalled in size and weight. Many 

 eminent cultivators join in the same opinion of magnesian lime deriA'ed from actual 

 practice.' (' A Treatise on Manures,' by J. Donaldson, pp. 157-8.) 



This experiment is very instructive and conclusive, for on comparing the results 

 obtained with the constituents of each of the various crops, it will be observed that 

 the beneBcial results were in proportion to that of the magnesia which the ash 

 contains. Though the green crops were good, it is specially mentioned by Donaldson 

 that the space which had the double allowance of magnesian lime 'showed no 

 difference in the turnip crop.' 



The following table, extracted from ' How Crops Grow ' (Eng. ed. by Church 

 and Dyer), gives the percentage of magnesia and lime in the ashes of the crops 

 alluded to : — 



Uagnesia Lime 



Turnips (mean of 3 sorts) .... 2-9 11-2 



Hay 4-9 11-6 



Barley straw ...... 2'4 7 "6 



„ seeds 8-3 2-5 



Beet 8-9 63 



Wheat straw 26 62 



„ seeds 12-2 31 



We here see that Donaldson's results are exactly in accord with what would 

 have been predicted from a consideration of the mineral constituents of the different 

 crops. The turnip, containing the smallest proportion of magnesia, is not benefited 

 by tlie presence in the soil of a double proportion of that substance; probably the 

 200 bushels to the acre of Breedon lime supplied quite enough lime and more 

 magnesia than was necessary for that crop : but in the case of wheat, where for 

 the formation of the seed a Aery large supply of magnesia was necessary, the dose 

 of 200 bushels to the acre was insufficient to enable the roots to find the requisite 

 amoimt of magnesia for the fuU development of the crop, and yet, if, in this 

 matter, we are to follow-M. Ville's prescription, all the soils naturally contain enough 



