808 Dr Daubeny m separating Lime from Magnesia. 
given quantity of sulphate of lime, through the agency of the“ 
oxalic test. 
To confirm this observation, and likewise to ascertain whcr 
ther the precipitate of the lime could be altogether prevented 
by the influence of a predominating portion of the magnesian 
sulphate, I tried the effects of the test upon mixtures of the 
two salts, in the following proportions, noting the effects at the 
time of the addition, and at an interval of one hour, and twen- 
ty-four hours afterwards. 
Proportion of the Ingre- 
dientSj being 
Rendered the Liquor 
Oxalate of Ammonia added to 
\. 
J 
Y 
V 
Sulph. 
Sulph. 
at the time 
1 hour af- 
24 hours 
Water, 
Magn. 
Lime. 
terwards 
afterwards 
1. A , saturated solu-'J 
very tur- 
very tur- 
very, tur- 
tion of sulph. of v 
480 
1 
bid. 
bid. 
bid. 
lime, j 
' ^ 
2. Saturated solution x 
of sulph. of lirafe, f , 
Solution of sulph. 
very 
very tur- 
tery tur- 
960 
25 
1 
slightly 
bid. 
bid. 
of magnesia 25 i 
gi\ to the 1 oz. ' 
turbid. 
3. Sol. of sulph. lime, 1 part. ) 
1440 
1 
slightly 
very tur- 
very, tur- 
Distilled water, 2 parts, J 
turbid. 
bid. 
bid. 
4. Sol. of sulph. lime, 1 parti 
Sol. of sulp, magnesia 25 V 
gr. to th6 1 oz. 2 parts, j 
1440 
50 
1 
caused no 
effect. 
less tur- 
bid than 
No. 3. 
very tur- 
bid. 
5. Sol. of sulph. lime, a 
Sol. of sulph. mag- / , 
hesia, containing ^ 
5Q gr. to the.l A-P 
oz. 
960 
50 
1 
very slight 
effect; less 
than in 
No. 2. 
slightly 
turbid. 
very tur- 
bid. 
6. Sol. of sulph. lime, 1 Part 1 
Sol. of sulp. magnesia 50 > 
gr. to the 1 oz. 2 parts, j 
7. Sol. of sulph. lime, \ 
1440 
100 
1 
caused no 
effect. 
caused no 
effect. 
slightly 
turbid. 
Sol. of sulph. mag- ? equal 
960 
100 
1 
caused no 
slightly 
slightly 
nesia, 100 grains | parts, 
to the 1 oz. " 
eflfect. 
effect. 
turbid. 
It will be seen from the above experiments, that the inertness 
of the oxalic test cannot be wholly attributed to the mere dilu- 
tion of the sulphate ; for in experiment 3. the salt was diffused 
through the same quantity of water as in No. 4. and 6., and yet 
the effects were very different. Nor could it be owing to any 
strange affinity between the oxalic acid and the magnesia, for a 
reference to the common Tables of Affinity will shew ' us, that 
lime decomposes the oxalate of magnesia ; arid accordingly, if 
only a few drops of the solution of an oxalate be added to one 
