it 6 Dr. Henry's Analysis of several Varieties 
from the sulphate of lime, 21 grains, the sum of which is 59, 
But the quantity actually obtained was 59.8. There is only, 
therefore, an excess of 0.8 grain of the actual above the es- 
timated quantity, a difference much too trivial to be admitted 
as an indication of any sulphate with an alkaline base ; and 
arising, probably, from unavoidable errors in the experiment. 
(F. a.) If in any mixture of salts, free from the earthy 
muriates, we are certain that no other sulphates exist beside 
those of lime and magnesia, their estimation becomes ex- 
tremely simple. Decompose two equal quantities of the salt 
in question, the one by muriate of barytes, the other by oxa- 
late of potash. From the weight of the latter precipitate, we 
may calculate the quantity of sulphate of lime. Suppose, for 
example, the oxalate of lime (as was actually the case with 
the precipitate from 1000 grains ofLymington salt,) to weigh 
12 grains ; these denote 15 of sulphate of lime, dried at 160° 
Fahrenheit, which quantity, if decomposed, would give 2o£ 
of sulphate of barytes. The latter number (ao£), subtracted 
from the weight of sulphate of barytes actually obtained (say 
60), gives 39^ grains for the sulphate of barytes, resulting 
from the decomposition of sulphate of magnesia. The quan- 
tity of the latter salt, it will be found, therefore, by applying 
the rule already given (D. e.), must be 35 grains. 
(F. b. ) The same object may be accomplished by decom- 
posing two equal quantities, the one by oxalate of potash, the 
other by the compound solution (D. c.). From the weights 
of the precipitates, it is easy to calculate from how much of 
the calcareous and magnesian sulphates they have resulted. 
(G.) When the salt left by alcohol was known to contain 
muriate of soda, and sulphate of magnesia, but no sulphate of 
