AND SOME OF ITS DERIVATIVES. 407 
Its aqueous solution reacts strongly acid, and readily coagulates the white of 
eggs. It imparts to persalts of iron a deep red colour. It decomposes carbonates 
with effervescence. 
It is bibasic, forming two series of salts, the acid ones are readily crystal- 
lisable ; its salts are very stable, the acid being recoverable from them by decom- 
position with stronger acids. 
Acid Ethylomeconate of Baryta—When carbonate of baryta is added in suc- 
cessive small quantities to water covering solid ethylomeconic acid, lively effer- 
vescence ensues and the acid quickly disappears; there is formed at the same 
time a small amount of an insoluble yellow salt. If the fluid be filtered imme- 
diately on the cessation of the effervescence, and the vessel be placed under the 
receiver of an air-pump and a vacuum made, a considerable deposit of carbonate 
of lime, which had been held in solution by the carbonic acid now liberated, takes 
place. By a second filtration a clear yellowish fluid is obtained, which yields, on 
evaporation in vacuo or at a gentle heat, very well-defined brilliant rhombic crys- 
tals of a yellow colour. A specimen prepared in this way gave the following 
results :— 



5-058 grains, dried at 212°, gave 
6-708 ... carbonic acid, and 
1:198 ... water. 
‘ 5-455 grains, dried at 212°, gave on ignition with HO SO,, 
2:175 ... sulphate of baryta. 
Calculation. 
Carbon, . 4 36-20 36°53 C,, 108 
Hydrogen, . : 2°63 2°36 i 
Oxygen, . : noe 35°19 O,, 4104 
Baryta,  . ; 26°17 25-92 BaO 76:64 
100-00 100-00 -295°64 
which lead to the formula, for the dried ethylomeconate of baryta, of 
BaO, HO, C,H,0 C,, HO,,. 
The crystals contain water which they lose on drying, but I missed ascertaining 
the quantity. 
Acid Ethylomeconate of Silver —I obtained this salt by adding an aqueous solu- 
tion of the former to nitrate of silver; a precipitate was immediately formed, which, 
upon resolution in boiling water, after washing, crystallised out on cooling of the 
fluid in groups of fine small stellate crystals, brilliant and white. This salt is 
remarkably stable, remaining perfectly unchanged in appearance when exposed a 
long time to the diffused daylight of summer; it gave the following results on 
analysis :— 

6-215 ... carbonic acid, and 
5-310 grains, dried at 212°, gave 
1:053 ... water. 

