Am.  Jour.  Pbariu.  i 
January,  1908.  J 
Assaying  Errors. 
39 
ASSAYING  ERRORS. 
When  the  Manufacturers'  Committee,  called  together  by  the  Pure 
Food  and  Drug  Act  Commissioners,  met  in  New  York,  September, 
1907,  we  called  attention  to  the  fact  that  certain  conditions,  likely 
to  make  errors  in  returns,  might  be  met  when  certain  preparations 
on  the  market  were  assayed,  one  of  these  being  a  change  in  alco- 
holic strength,  without  any  evaporation  of  alcohol  whatever,  which 
would  take  place  in  securely  sealed  containers.  Our  experience  in 
a  study  of  "  Precipitates  in  Fluid  Extracts ,"  thirty  years  ago,  had 
brought  to  our  attention  the  fact  that  whenever  an  alcoholic  liquid 
casts  a  precipitate,  the  liquid  becomes  stronger  in  its  percentage  of 
alcohol.  Consequently,  a  fluid  extract  that  contains  50  per  cent, 
alcohol  when  freshly  made,  and  which  throws  out  a  sediment,  will 
assay  above  50  per  cent,  after  precipitation.  The  alcoholic  propor- 
tion increases  with  the  amount  of  the  precipitate  that  separates. 
In  order  to  establish  the  result  of  precipitation,  a  number  of  resin- 
bearing  liquids  of  known  alcoholic  strength  were  recently  mixed 
with  their  own  bulk  of  water,  the  sediments  allowed  to  separate,  and 
the  overlying  liquids  then  assayed,  the  result  being  multiplied  by 
two  in  order  to  bring  them  back  to  the  proper  proportion,  they 
being  now  only  half  the  strength  of  the  original  liquids.  In  each 
instance  there  was  a  decided  increase  in  the  proportion  of  alcohol, 
as  shown  in  the  accompanying  table. 
r-^t,^        After  Precipi- 
Name.  fJfa     X  tation  has 
Assayed.  occurred. 
Per  cent.  Per  cent. 
Podophyllum   53  65 
Eriodyction   77  86 
Leptandra  .   .61  62 
Jalap   83  98 
Grindelia   83  90 
Cimcifuga   68  70 
Hydrastis   71  72 
This  is  one  of  the  features  that  will  be  investigated  carefully  by 
the  Government,  and  proper  allowance  made  therefor.  We  take  it, 
no  dealer  or  manufacturer  need  expect  prosecution  by  reason  of  an 
occurrence  indicated  by  such  problems  as  this. — John  Uri  Lloyd, 
Eclectic  Medical  Gleaner,  Vol.  Ill  (1897),  No.  6,  p.  505. 
