Am.  Jour.  Pharnj.  t 
April,  J9(j8.  > 
Oil  of  Bitter  Almonds. 
155 
presence  of  hydrocyanic  acid  in  the  oil  is  always  certain  if  it  be 
genuine  and  has  not  been  treated  to  remove  this  constituent,  but 
the  presence  of  the  acid  is  by  no  means  a  guaranty  of  its  genuine- 
ness, for  we  will  find  oils  consisting  of  benzaldehyde  to  which  has 
been  added  the  requisite  amount  of  hydrocyanic  acid  to  meet  the 
requirements  of  the  trade  or  of  the  Pharmacopoeia.  The  U.S. P. 
tests  are  as  comprehensive  and  exacting  as  we  can  well  expect,  and 
there  is  good  reason  to  believe  that  an  oil  which  will  meet  these 
tests  is  an  excellent  one;  but  it  would  appear,  after  an  examination 
of  results  which  are  here  submitted,  that  some  of  these  requirements 
are  erroneous,  particularly  the  assay  for  benzaldehyde.  Subjoined 
in  tabular  arrangement  are  the  results  of  the  application  of  the 
United  States  Pharmacopoeia  tests,  with  the  exception  oi  the  benzal- 
dehyde assay  (which  will  be  treated  of  separately),  to  twenty-two 
samples  of  oil  derived  from  various  sources  : 
Specific 
Solubility 
Chlorinated  Compounds 
Hydrocyanic  Acid 
Gravity 
in  70  per  cent. 
Copper  AgNTOg 
Qualitative. 
Quantitative 
No. 
at  130 
Alcohol. 
Test.  Test. 
Per  cent. 
I. 
1*064 
IO 
absent  absent 
present 
2  23 
2. 
1*063 
ro 
present  present 
absent 
3- 
I"054 
1*6 
absent  absent 
4. 
I  '054 
ro 
present  present 
5- 
I  055 
10 
<  t 
6. 
I '053 
I'O 
7. 
1*058 
i*o 
8. 
1*051 
I'O 
absent  absent 
9- 
I -075 
0*9 
present 
6-44 
10. 
I  ""5  I 
I'O 
absent 
11. 
I -054 
I'O 
present  present 
12. 
1*072 
0*9 
13- 
I*058 
0  95 
a                  <  < 
present 
1  24 
14. 
I  '060 
I'O 
<  s                                          (  « 
absent 
15. 
I*o62 
095 
present 
0*69 
16. 
1 .063 
o"95 
3"3i 
17. 
I -053 
10 
ti  (( 
absent 
18. 
I-058 
I'O 
<(  (( 
« « 
19- 
I.068 
095 
present 
~3"29 
20. 
i  'ot)8 
o*95 
( <                       ( < 
<« 
3*28 
21. 
1  057 
I'O 
« < 
09 
22. 
1  '060 
I'O 
<  <                         <  < 
absent 
Specific  Gravity. — The  specific  gravity  recorded  by  the  U.S  P.  of 
1-045  to  1-060  at  25  0  is  about  equivalent  to  1*052  to  1  067  at  150  C. 
These  (1-045  to  1*060)  are  the  limits  for  150  C.  as  given  by  Gilde- 
