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Of the fulphureous Mineral Water of Fairburn, 



Dr. Mackenzy in his letter mentioned no more of 

 this than that he believed it to be a weaker water, 

 of the fame nature as the Caftle-Loed. 



I fubje&edit to the fame tryals, as it: on opening 

 the bottles, it emitted a ftrong fulphureous fmell, 

 tinged filver, and produced nearly the fame ap- 

 pearances as the Caftle-Loed when mixed" with the 

 fame fubftances, only it remained clear when a fo- 

 lution of the true foffii alkali was mixed with 

 it ; the cauftic vegetable alkali occasioned a very 

 fmall light, darkifh cloud, and precipitated but a 

 very fmall quantity of a VQty light fediment, ow- 

 ing, as appeared afterwards, to this water containing 

 an abforbent or calcarious earth, which probably 

 was fufpended by air, and but very little if any 

 felenite. 



I evaporated lib. viii. drachm, i. fcrup. i. (or 1 28 

 ounces, four fcruples) of this water with a flow fire. 

 When it was evaporated to one half, it was filtrated 

 through paper; which operation was repeated again, 

 when reduced to three ounces $ after which the re- 

 mainder was evaporated to drynefs, and the folid 

 matter left, thrown into diftilled water, filtrated 

 again through paper, and evaporated to a pellicle, 

 and fet in a cool place for the falts to cryftallife. 



By thefe operations, I obtained near gr. ii, of a 

 dark coloured light earth, which effervefced with 

 acids, and diffolved j gr. xv. of a white calcarious earth, 

 which effervefced with and diffolved in the vitriolic 

 acid j — and gr. xxiv. of Glauber falts mixed with a 



Vol. LXIL E yellow 



