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SELECTED ARTICLES. 
by iodine, the presence of a, considerable quantity of amidon; 
upon precipitating this liquor when concentrated, by alcohol, 
it was separated into a flocculent magma, which when dry, 
was not pulverulent, but existed in the form of a gummy coat- 
ing, and weighed about 2 grammes: the amylaceous matter 
doubtless had been modified in this operation. 
4. It only remained to investigate the composition of the 
insoluble residue, in which I had already ascertained the ex- 
istence of oxalate of lime and of phosphate and sulphate of the 
same, besides lignin or ligneous fibre, and pectin, with pectic 
acid. I separated this insoluble residue, which was dry, cori- 
aceous and brown, into two equal portions, A and B. 
Operation A. — The coriaceous matter, calcined strongly 
in a platina crucible, gave off empyreumatic fumes, associated 
with products slightly azotized. The residue of this prolonged 
calcination was of a dirty white colour; treated with diluted 
muriatic acid, a rapid disengagement of carbonic acid took 
place, mixed with traces of hydrosulphuric acid, due to the 
small quantity of sulphate which the carbon had decomposed; 
the liquor being filtered and neutralized by an excess of am- 
monia, let fall a precipitate of phosphate of lime, and oxide of 
iron 0.25; filtered anew and oxalate of ammonia being added, 
an oxalate of lime was obtained, which when dry, weighed 
3.3 grammes, the weight being doubled, since but half the cori- 
aceous residue was used. 
Operation B. — In order to convince myself of the presence 
of oxalic acid in the organic salt which the heat had decom- 
posed in the preceding experiment, I reduced the coriaceous 
deposit into a sort of pap, by means of hot distilled water. I 
then mixed it with a small quantity of bicarbonate of potassa, 
and heated it to boiling. The mixture when filtered, produced 
a rose-coloured liquid, from which the addition of an acid sepa- 
rated gelatinous flocculi of pectic acid; filtered anew, the neutral 
acetate of lead was added to the liquid portion. The white 
precipitate being washed and treated in a capsule by sulphuric 
acid, produced, after several days, crystals of oxalic acid, easily 
to be recognised and most unequivocal. 
With regard to the insoluble gelatinous residue, when dry 
