400 
Mr Herschel on the Hi/posulphurous Acid, 
solubility in water, but readily and abundantly taken up by 
ammonia, giving an intensely sweet solution. If the water in 
which this salt is washed be evaporated ever so little, thin rhom- 
boidal plates, as acute as those of sulphate of lime, are formed 
on the surface while hot*, though the whole saline contents of 
the liquid are trifling. This salt suffers partial decomposition 
by keeping, though in a far less degree than the corresponding 
salt of ammonia. It seems, from some experiments, to contain 
its component salts united atom to atom. 
Hyposulphite of Strontia and Silver . — There seems to exist 
but one variety of this double salt ; at least when on the insolu- 
ble powder formed by the action of hyposulphite of strontia upon 
muriate of silver, an additional portion of the former is poured, 
very little, if any, is taken up ; the liquid acquires no percepti- 
ble sweetness, and scarcely affects hydrosulphate of potash. 
But the powder itself presents all the phenomena of a double 
hyposulphite, giving an intensely sweet solution with ammonia, 
and affording, by analysis, both the hyposulphites and a por- 
tion of the metallic muriate. 
Hyposulphite qf Lead and Silver . — When nitrate of lead is 
poured into a solution of hyposulphite of lime and silver, both the 
metallic hyposulphites separate in a white powder, but whether 
in combination or mixture seems not easy to determine. 
The estimation of any muriatic acid which may be present in 
these and similar compounds, seems most easily accomplished 
by nitrate of silver, made to act on them in excess, and assisted 
by heat. This, as I have shewn, determines the complete de- 
struction of the hyposulphurous acid, Sulphuret of silver is 
formed, mixed with muriate, should any of the latter acid be 
present. This may be, however, completely separated by treat- 
ing the precipitate (most carefully washed from any remains of 
the nitrate) with a weak solution of hyposulphite of soda added 
in repeated afiusions. The washings so obtained may be pre- 
cipitated by hydrosulphate of potash, and the precipitate which 
falls, corresponds after the usual reductions, to the muriate of 
silver or muriatic acid present. 
London, ) 
May'\5.'lS\% j 
