on iht Hyposulphurous Acid. 399 
ting paper j and dried in vacuo. It is very readily soluble in 
water. Its sweetness is unmixed with any other flavour, and so 
intense as to cause pain in the throat. One grain of the salt 
communicates a perceptible sweetness to 3S,000 grains of water. 
If the alcoholic liquid be evaporated, thin lengthened hexangular 
plates are sometimes formed, which are not altered by keeping, 
and consist of the same principles. 
When the hyposulphite of ammonia refuses to dissolve more 
muriate of silver, if an additional quantity be added, it is rapidly 
converted into a white crystallized powder. It is extremely in- 
soluble in water, but readily and abundantly in ammonia, forming 
an intensely sweet solution, from which an acid precipitates it un- 
altered, even when copiously diluted. Dried in vacuo, and kept in 
a closely stopped vessel^ it blackens and undergoes spontaneous 
decomposition. The phial, whenever opened, is found full of 
sulphurous acid ; and when washed with ammonia, a consider- 
able residue of sulphuret of silver is left. Heat effects the same 
change at once. 
S9.3 grains of the soluble variety above described gave 11.9 
sulphuret of silver, which agrees within moderate limits with a 
composition of S atoms hyposulphite of ammonia -f 1 atom hy- 
posulphite of silver. Hence it is very probable, that the inso- 
luble variety consists of the same component salts united atom 
to atom. 
Hyposulphites qf Lime and Silver . — When hyposulphite of 
lime is made to dissolve as much muriate of silver as it will re- 
tain, if alcohol in pretty large quantity be added, and well agi- 
tated, a white salt precipitates, which is found to retain scarce- 
ly any portion of muriatic acid after washing in fresh alcohol 
and forcible expression, the whole muriate of lime formed being 
carried off by the alcohol, which, on examination, is found to 
contain it in abundance. This proves the mutual decomposi- 
tion. This salt, however carefully dried in vacuo, leaves a 
portion undissolved when put in water. Like all the other salts 
of this class, it is intensely sweet, and is decomposed by a mo- 
derate heat. 
When an additional dose of muriate of silver is added to its 
saturated solution in hyposulphite of lime, it is immediately 
converted into a voluminous crystalhne powder of very difficult 
D d2 
