192 
ORIGINAL COMMUNICATIONS, 
porcelainous, and can be reduced to a powder, which rapidly 
absorbs from four to seven per cent, of water. 
According to several accurate analyses of the amygdalate 
of baryta, in which every precaution was taken respecting 
the hygrometric humidity in the apparatus, arising from the 
tenacity with which the salt holds water in combination, the 
following is offered by Liebig and Wohler as its composi- 
tion, viz.: 
40 atoms carbon, 3057.480= 45.519") f 45.335] 
4.814 { i 
52 " hydrogen, 324.469= 4.814 .! in 100 I 5.029 [ c 
24 " oxygen, 2400.000= 35.466 [parts. [ 36.458 [ J 
1 " baryta, 956.880= 14.199 J [ 13. 178 J 
1 " amyg. bar. 6738.829. 
Amygdalic acid can easily be obtained by precipitating its 
barytic salt with dilute sulphuric acid. It is a weakly acid 
liquid, which becomes syrupy, and finally a gummy mass on 
evaporation by a salt bath. 
It absorbs moisture from the air with avidity, and deli- 
quesces; it is insoluble in either cold or boiling absolute 
alcohol and ether, but is slightly soluble in hydrated alcohol. 
When boiled with peroxide of manganese, and a little 
sulphuric acid, it yields, by distillation, formic and carbonic 
acids, and oil of bitter almonds. The production of the last 
is an evidence of its existence ready formed in amygdalic 
acid. 
All the amygdalates undergo the same decomposition, and 
none, so far as Liebig and Wohler had examined, were 
insoluble but the amygdalate of lead. 
The composition of amygdaline, and that of amygdalic 
acid, are reciprocally confirmed. Amygdalic acid contains 
two atoms of hydrogen less, and two atoms of oxygen more 
than amygdaline ; if to the elements of amygdaline, two 
atoms of water be added, and two atoms of ammonia be taken 
away, there remains one atom of amygdalic acid; thus — 
N 2 C 40 H 54 O 22 + H 4 2 = N 2 C 40 H 58 O 24 — N 2 H 6 = C 40 H 52 O 24 . 
