368 DR ANDERSON’S RESEARCHES ON SOME OF THE 
Acid Hemipinate of Potass—This salt was met with at first accidentally in 
an experiment in which, during the preparation of the acid, a sufficient quantity 
of hydrochloric acid was not added to the original alkaline solution; but it may 
be readily prepared by dividing a quantity of hemipinic acid into two equal quan- 
tities, neutralising one half with potash, then adding the other and evaporating. 
It is deposited in thick six-sided tables sometimes of considerable size. It is 
readily soluble both in cold and hot water and in alcohol, but not in ether, which 
throws it down from its alcoholic solution in shining plates. It is highly acid 
to test paper. Dried at 212° it gave the following results : 


6-203 grains acid hemipinate of potass gave 
10-245 pe carbonic acid, and 
1935 ... water. 
5-330 grains acid hemipinate of potass gave 
1-763... sulphate of potass. 
Experiment. Calculation. 
Se 
Carbon, : : 45:04 45°42 Cy, 120 
Hydrogen, . ; 3°46 3°40 H, 9 
Oxygen, ; : ae 33°32 OF 88 
Potass, : : 17-88 17°86 KO 47-2 
100-00 
13°505 grains of the crystallised salt lost, at 212°, 1:950 grains =14-48 per cent., 
and corresponding to 5 equivalents of water, the calculated result for which is 
14:55 per cent. The formula of the crystallised salt is consequently, 
KO HO ©,, H, 0,,+5 HO. 
Neutral Hemipinate of Potass is a highly soluble salt, and crystallises only 
with difficulty. 
Neutral Hemipinate of Silver is obtained as a white precipitate, insoluble in 
water. Dried at 212° and burned, it gave the following results :— 
ee grains hemipinate of silver gave 

3098 =... ___ silver. 
Experiment. Calculation. 
Carbon, - : fae 97-27 (oe 211) 
Hydrogen, . : Soc 1-81 HH, 8 
Oxygen, = : aa 21°83 OF 96 
Silver, : > 49°34 49-09 Ag, 216 
100-00 440 
Acid Hemipinic Ether—Hemipinovinic Acid.—When hemipinic acid is dis- 
solved in absolute alcohol, and a current of hydrochloric acid gas passed through 
the solution, hemipinovinic acid is formed. It is obtained in the pure state by 

: 
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