Ee ea 
Rey ks en IN IN 
To difcover whether any quantity of fixed alkali worth atten- 
tion exifts in any faline compound, diffolve one ounce of it in 
boiling water, and into this folution let fall a drop of a folution 
of fublimate corrofive ; this will be converted into a brick colour, 
if an alkali be prefent, or into a brick colour mixed with yellow, 
if the fubftance tried contains lime. 
Bur the fubftances ufed by bleachers being always impregnated 
with an alkali the above trial is in general fuperfluous, except 
for the purpofe of dete€ting lime. The quantity of alkali is 
therefore what they fhould chiefly be folicitous to determine, and 
for this purpofe : 
rft, Procure a quantity of allum, fuppofe one pound, reduce it 
to powder, wafh it with cold water, and then put it into a 
tea-pot, pour on it three or four times its weight of boiling 
water. 
adly, Weigh an ounce of the afh or alkaline fubftance to be 
tried, powder it and put it into a Florence flafk with one pound 
of pure water, (common water boiled for a quarter of an hour, 
and afterwards filtered through paper, will anfwer) if the fub- 
{tance to be examined be of the nature of barilha or pot-afh; or 
half a pound of water if it contain but little earthy matter, as 
pearl-afh ; let them boil for a quarter of an hour, when coo! let 
the folution be filtered into another Florence flafk. 
3dly, 
