fours 
Springs at Lemington Priors. 197 
a black substance is formed ; but the hepatic odour 
was not destroyed, though the hepatic gas was kept 
in contact with the mercury many weeks. After fil- 
trating the liquor, I boiled it to expel the super- 
fluous hepatic gas. A small portion of the liquor 
was suffered to evaporate spontaneously: a crystal- 
line matter was left behind of an acrid taste. Ano- 
ther portion was evaporated, with intention to col- 
lect more of these crystals ; but, by accident it was 
left exposed to heat too long, by which it became 
perfectly dry, and the residuum became quite black. 
A little sulphuric acid was dropped on this black 
matter, by which it effervesced strongly, and very 
pungent fumes arose which Sos all the properties of 
muriatic acid. 
XI.’ FURTHER PROPERTIES OF THE OXYGE- 
NATED MURIAT OF IRON, 
The facts I have related are unquestionable: it 
was in the latter end of the year 1795 that I first 
made the observation on the effect of hepatised wa- 
ter upon iron; since this time I have verified it re- 
peatedly, and particularly in the month of Decem- 
ber, 1796, with some very pure iron, and in the 
presence of two gentlemen, very competent judges, 
one of whom assisted at every part of the process. 
Still it has been asked, how is it possible that this 
solution can contain muriatic acid, seeing that ni- 
trat of silver, that most delicate test of this acid, is 
