346 Comparative Analysis of the Gum Resins. 
turbid’ on’ coolirig; and at the end of two days there was de- 
posited an abundant white gelatinous-like matter, which 
when’ washed in alcohol and'dried weighed 4-7 grammes: it 
still retained alcohol, which I drove off by melting it at a 
gentle heats’ it did not then weigh more than 3:4 grammes. 
This substance was semi-transparent, it easily became soft 
under the fitigers, was almost entirely volatilized' om hot iron, 
and acted! like bees-wax, of which it even had the smell 
when melted or burnt. 
The wax of euphorbia preserved a little acrimony, with- 
out doubt because it had not been sufficiently washed in 
alcohol. ‘'1 made a taper of it, which burned with a very 
pure flame. 
C. The 6:4 decigrammes of the matter insoluble in al- 
cohol A were heated to the boiling point with 100 grammes 
of distilled water. The filtered liquor left smail branches 
of wood and thors, on which the euphorbia was stuck : 
after desictation it weighed 2-7 erammes. 
D. The aqueous solution C when evaporated formed a 
varnish on the surface of the’vessel. On thickening it to 
dryness, we dbtained-a fragile substance, which was removed 
in‘micaceons scales: it did not-attract humidity from the 
air, and weighed 4+) grammes, which I recognised at first 
sight as malate of lime. In short, upon heating this sub- 
stance with sulphuric acid diluted in water, | obtained, 
Ist, some very white sulphate of lime, which after being 
washed and dried weighed 1*6 grammes: @d, an acid 
which alcohol dissolved, and from which there were sepa- 
rated five decigrammes of sulphate of lime.) The solution 
when evaporated produced two grammes of malic acid, re- 
taining a little sulphuric acid, whieh was‘taken from it by 
means of barytes. serait 
The malate of lime seems’to exist therefore in’a consi- 
derable quantity in the lactiform juice of eupborbia, and it 
is this which in the euphorbia of commerce was anciently 
supposed to be a gum, and which has been confounded 
with the extractive matter by M. Laudet,.a late experimenter. 
EK. The alcoholic solution B, when evaporated to dryness, 
left a residue weighing 8°3 grammes, which were treated by 
cold aléohol, aiid which dissolved the’ resinous particles, 
and also separated four decigrammes of wax. 
-F, This solution was again thickened, and we obtained 
a resin attracting a little humidity from the air, which must 
have been owing to a deliquescent salt which T obtained on 
heating this resin with distilled water. This’salt was malate 
Of potash, and weighed four decigrammes when well dried. 
aed G. The 
