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AQUA HAMAMELIDIS. 
Hamameli* TVater. 
The final product here is a distillate, while the old Extraetum 
Hamamelidis Fkiidum is a percolate now designated Fluidextractum 
Hamamelidis Foliorum. 
The aqua contains about 15 per cent of alcohol. 
Dose. — "Average dose: 8 C’e. (2 fluidrachmsy” (U. S. P. ) 
This preparation is almost identical with Aqua Hamamelidis Spiri- 
tuosa. X. P. 
BENZALDEHYDOI. 
Benzaldeliyde. 
C 6 H 5 CHO 
"Produced artificially or obtained from natural oil of bitter almond 
or other oils, and containing not less than 85 per cent of pure 
benzaldehy de. " 
Properties. — 4 * Colorless. strongly refractive liquid, having- a bitter- 
almond-like odor and a burning, aromatic taste.” "Sparingly soluble 
in water (1:300): soluble in all proportions, in alcohol, ether, and 
fixed and volatile oils.” 
Synthetic benzaldehyde is usually prepared from benzylehloride or 
benzylideneehloride: unless carefully purified, such benzaldehyde will 
contain chlorinated products (hence the U. S. P. test for these: cf. also 
Oleum Amygdalae Amaraey 
Unless properly prepared the benzaldehyde obtained from, the nat- 
ural oil of bitter almond may contain prussic acid (hence the U. S. P. 
test for this substance). 
Benzaldehyde is the principal constituent ‘of natural oil of bitter 
almond. The U. S. Pharmacopoeia. Eighth Decennial Revision, 
demands that the official oil of bitter almond contain not less than 85 
per cent of benzaldehyde. The natural oil of bitter almond also con- 
tain- hydrocyanic acid: the Eighth Decennial Revision demands that 
the official oil contain not less than 2 per cent nor more than 4 per 
cent of hydrocyanic acid. The commercial natural oils of bitter 
almond contain from 1.5 to 11 per cent, or more, of hydrocyanic acid: 
hence (unless the hydrocyanic acid has been removed) they should be 
used with great caution as flavoring agents. 
Dose. — "Average dose: 0.03 Cc. (4 minimi.” (II. S. P.) 
Caution. — It should be kept in small, amber-colored, well-stoppered 
bottles, as it is readily oxidized to benzoic acid: the latter change 
occurs more rapidly with the pure benzaldehyde than with the nat- 
ural oil of bitter almond. 
Nitrobenzene is an oil having an odor very much like that of oil of 
bitter almond; it is known as "artificial oil of bitter almond." or 
i; essence of mirbane.” It is sometimes used as a substitute for the 
oil of bitter almond in the manufacture of soap, cheap confectionery, 
etc. It is very poisonous. 
