THE CHEMICAL CONSTITUTION OE NAKCOTINE. 
661 
opianic acid. It reduces salts of silver in the cold, so that to determine its basicity we 
employed its barium-salt, from the analysis of which it appears that this new acid is 
monobasic. 
0-240 grm. gave 0-113 sulphate of barium. 
Calculated. Eound. 
, /V 
2(C 9 H 7 0 4 ). ... 358 72-32 
Ba 137 27 68 27-50 
3. Action of Hydrochloric and Hydriodic Acids on Hemipinic Acid. 
In our former paper we have (p. 355) described the action of hydriodic acid on hemi- 
pinic acid. We there stated that when hemipinic acid is treated with hydriodic acid 
the following reaction takes place : — 
C 10 H 10 0 6 .+2H I=C 0 2 +2 C H 3 1 + C 7 H 6 0 4 . 
The acid C 7 H 6 0 4 we called hypogallic acid. 
We also mentioned (p. 359) that when hemipinic acid is heated with strong hydro- 
chloric acid, the reaction is 
c,„ H 10 0 6 + H C1=C 0,+CH, Cl+C 8 H s 0 4 . 
The further investigation and analyses confirm this formula, 
^8 -^-8 0 43 
for this acid ; and as it contains one molecule of methyl more than hypogallic acid, and 
may be converted into that body by the prolonged action of hydrochloric acid, it may be 
called methyl-hypo gallic acid. 
One of the simplest modes of preparing this acid is to digest the hemipinic acid with 
strong hydrochloric acid on a water-bath at 100° C. under a layer of paraffin for about 
three days. The purification of the acid is very simple, owing to its being almost inso- 
luble in cold and sparingly soluble in hot water, whence it crystallizes out on cooling- 
in long transparent prisms. The crystals contain no water of crystallization. 
I. 0-4020 grm. gave 0-8460 grm. carbonic acid and 0-1786 grm. water. 
II. 0-5140 grm. gave 1-0700 grm. carbonic acid and 0"2276 grm. water. 
Calculated. Eound. 
c 8 . . . . 
. 96 
57-14 
I. 
57-39 
H. 
56-79 
h 8 . . . . 
8 
4-76 
4-93 
4-92 
0 4 . . . . 
. 64 
38-10 
— 
— 
c 8 h 8 o 4 . . 
. 168 
100-00 
The basicity of the acid was determined by precipitating the ammonium salt with 
nitrate of silver; the silver-salt is white, crystalline, rather insoluble in cold, soluble 
in hot, and decomposes in boiling waiter. 
0-3596 grm. silver-salt gave 0-1408 metallic silver. 
4x2 
