Dr. Thomson on Oxalic Acid. 
6 9 
7 acid, or per cent. 6 2.5 acid 
4.2 lime 37.5 base 
11.2 100.0 
Thus we have obtained exactly the same result as in the 
former experiment, both as far as relates to the composition 
of oxalate of lime, and likewise to the proportion of water of 
crystallization in crystallized oxalic acid. 
The lime water necessary to saturate the acid amounted to 
3186 grains. Hence, it contained only yj-gth of its weight of 
lime. 
3. The oxalates of barytes and strontian are white, tasteless 
powders, which may be obtained by mixing oxalate of 
ammonia with the muriates of these alkaline earths. It is said 
that these earths are capable of forming soluble superoxalates 
with this acid ; but I have not tried the experiment. These 
oxalates, as well as oxalate of lime, are partially soluble in the 
strong acids. 
4. Oxalate of magnesia is a soft white powder, bearing a 
considerable resemblance to oxalate of lime. It is tasteless, and 
not sensibly soluble in water ; yet when oxalate of ammonia 
is mixed with sulphate of magnesia, no precipitate falls ; but 
if the solution be heated and concentrated sufficiently, or if it 
be evaporated to dryness, and redissolved in water, in both 
cases the oxalate of magnesia separates in the state of an in- 
soluble powder. 
5. Oxalate of potash readily crystallizes in flat rhomboids, 
commonly terminated by dihedral summits. The lateral edges 
of the prism are usually bevelled. The taste of this salt is cooling 
and bitter. At the temperature of 60° it dissolves in thrice its 
weight of water. When dried on the sand bath, and afterwards 
