NATURE AND DETECTION OF METALLIC rOlSOXS. 3 I 1 



the means of precipitating any lead which may happen to be 

 dissolved in the water, but has the effect also of completely 

 coating the interior surface of the vessels with the sulphate 

 thus formed, which is a substance not liable to decomposition, 

 afnd therefore defends the lead from all future action of any 

 solvent in the mineral water, 



The dreadful disease called the Devonshire colic was clearly Devonshire 

 shown by Sir George Baker to be occasioned by the lead "con- ^'°'''^- 

 stiiuting the lining of the cider press, and other vessels, and 

 ■wrhich was dissolved by the acetic acid developed during fer- 

 mentation. The acetic acid is here asserted to be the solvent, 

 because the malic acid forms a salt with lead which is insoluble. 



The effects of this metal have been still more conspicuous Great injury 



in its use by wine merchants to correct the acidity of wine, 'lo''^ ''')' wine 

 rr.i • ^ ■ • T-. , . . merchants. 



Ihe practice was at one time so common in Fiance, that in a 



particular year, when much sour wine prevailed, many thou- 

 sands of people are said to have fallen victims to its influence ; 

 and had it not been for the interference of government, it is 

 impossible to say how widely this dreadful evil might have ex- 

 tended itself. 



In the new rum of our West-India colonies the presence Lead presect 

 of lead has been marked by still more deadly consequences. '" ^^^'^ "■"""• 

 It became a matter of great surprise, however, that, after this 

 liquor had been kept in casks for twelve months, it lost its dele- 

 terious qualiiies. The lead employed in the vessels for the 

 manufacture, but more especially in those for the distilia- 

 tipn of rum, could not fail to introduce this metal in great 

 quantity through the medium of the acetic acid, which is a con- 

 stant product of fermentation 5 and had it not been for a cir- 

 cumstance about to be mentioned, it is difficult to conceive 

 where the calamity might have terminated. Nature, however, 

 in the shape of accident, stepped in as mediator, and redeemed 

 the lives of those destined to drink the fascinating potion. It 

 was before observed, that the rum lost its poisonous property 

 by remaining a certain time in the caslcs ; yet, although the 

 fact was known, and the evil remedied, many years ago, I am 

 not aware that any one has accounted for the change produced ^^^^ ^-^^ -^ 

 in the liquor. About two years since, my friend. Dr. Forester, remedfed by ' 3 

 of this place, gave an interesting lecture, on behalf of the l^^P'^s- 

 Literary and Philosophical Society, upon the subject of poisons j 



and 



