147 
and naphthaline , and on a new acid produced. 
The barytic salt in solution was now very carefully de- 
composed, by successive additions of sulphuric acid, until all 
the baryta was separated, no excess of sulphuric acid being 
permitted. Being filtered, a pure aqueous solution of the 
peculiar acid was obtained. It powerfully reddened litmus 
paper, and had a bitter acid taste. Being evaporated to a 
certain degree, a portion of it was subjected to the continued 
action of heat ; when very concentrated it began to assume 
a brown colour, and on cooling became thick, and ultimately 
solid, and was very deliquescent. By renewed heat it melted, 
then began to fume, charred, but did not flame ; and ulti- 
mately gave sulphuric and sulphurous acid vapours, and left 
charcoal. 
Another portion of the unchanged strong acid solution 
was placed over sulphuric acid in an exhausted receiver. In 
some hours it had by concentration become a soft white 
solid, apparently dry ; and after a longer period was hard 
and brittle. In this state it was deliquescent in the air, but 
in close vessels underwent no change in several months. Its 
taste was bitter, acid, and accompanied by an after metallic 
flavour, like that of cupreous salts. When heated in a tube 
at temperatures below 21 2 °, it melted without any other 
change, and on being allowed to cool, crystallized from 
centres, the whole ultimately becoming solid. When more 
highly heated, water at first passed off, and the acid assumed 
a slight red tint ; but no sulphurous acid was as yet pro- 
duced, nor any charring occasioned ; and a portion being 
dissolved and tested by muriate of baryta, gave but a very 
minute trace of free sulphuric acid. In this state it was 
probably anhydrous. Further heat caused a little naphthaline 
