Vn the iifftrmt Sorts ofLtine ufed in Agriculture. 4^ 



confulered as the fame fpecics of ftone, but in a ftatc of greater purity. The piece* 

 of dolomite were from different places, one of them being found among the ruins of 

 Rome, where it is thought to have come from Greece, as many ftatues of Grecian work- 

 ipandiip are made of it, and no quarries of a fimilar kind are known in Italy ; the fc- 

 cond was faid to have been thrown up by mount Vefuvius ; and the third was from 

 Tona, one of the weftern iflands of Scotland. In many kinds of common marble 

 fmail particles of veins may be obferved, which are a long time In diffolving. Thefe, 

 upon examination, I difcovered to contain a confiderable portion of magnefia; but aS 

 they were probably not quite free from the furrounding marble, I did not afcertain the 

 quantity precifely. 



The chryftallized flrufture which may generally be obferved in the magnefian Hme- 

 ilone feems to fhew that is has not been formed by accidental union of the two earths, 

 but muft have refulted from their chemical combination. The difficulty of diffolving it 

 may alfo arife from the attraftion of the different component parts to each other. The 

 mortar foundf rom this kind of lime is as foluble in acids as common marble, and the 

 fubflances of which it confifts are eafily feparated. The magnefia may be taken froni 

 it by boiling it in muriated lime, and lime is precipitated from it by lime water ; but 

 neither of thefa effefls can be moderated by the ftone before it is calcined. 



Magnefian lime-ftone is probably very abundant in various parts of England. It ap- 

 pears to extend for thirty or forty miles from a little fouth-weft of Workfop, in Not- 

 tinghamdiire, to near Ferry Bridge, in Yorkfhire. About five or fix miles further 

 north there is a quarry of it near Sherburn ; but whether this is a continuation of the 

 ftratum near Ferry Bridge I have not learnt. From fome fpecimens which were fent 

 me I find that the cathedral and molls of York are made of it. I have not been able 

 to learn whether there were any fliellsin the lime-ftone of the traft of the country be- 

 fore mentioned. • In Mr. Mar/hall's, account of the agriculture of the Midland coun- 

 ties, he fpeaks of the lime made at Breedon, near Derby, as deftru£iive to vegetables 

 wfien tifed in large quantities. I therefore procured fon\e pieces of it, and they were 

 iJifcovered to contain nearly the fame proportion of magnefia as that beiore defcribed. 

 In this quarry the ftone is frequently cryftallized in a rhomboidal form, and petrefied 

 fhells, not calcareous, but fimilar in compofilion to the ftone itfelf, ■ are fometimes but 

 very rarely found in it. This fubftance feems to be common in Northumberland. la 

 the third vol. of the Annals of Agriculture Dr. Fenmck, of Newcaftle, obferves that 

 the farmers of that country divide limes into hot and mild. The former of thefe is n», 

 doubt magnefian, as it has fimilar effefts on the foil, and he remarks that it is not fo 

 eafily diffolved in acids as the latter. At Matlock, in Derbyfliire, the two kinds are 

 contiguous to each other ; the walks on the fide of the river where the houfes are built 

 isemg magttefian, and on the other calcareous. The magnefian rock appears alfo to be 



incumbent 



