540  Valuation  of  Drugs  and  Foods.  {iSveSbefS**' 
rich  in  tannin  as  those  not  so  affected.  A  rather  careful  examination 
of  the  better  grades  of  commercial  specimens  of  galls  discloses  the 
fact  that  in  from  5  to  7  per  cent,  of  the  galls  the  insect  has  emerged 
as  indicated  by  the  perforation.  Upon  opening  the  remaining  93, 
to  95  per  cent,  of  galls,  it  is  found  that  not  more  than  from  10  to 
12  per  cent,  are  hollow  and  contain  the  large  grubs  or  young 
winged  insects.  The  remainder  should  be  nearly  solid  throughout, 
and  the  appearance  should  be  more  or  less  grayish  and  crystalline,, 
or  at  the  most  light  yellowish  and  resinous  in  appearance.  Galls 
answering  to  these  characters  will  assay  50-60  per  cent,  of  tannin. 
(Z?)  The  specific  gravity  of  at  least  some  drugs  has  seemed  to  the 
author  deserving  of  consideration  in  ascertaining  their  commer- 
cial value.  Last  year  I  was  fortunate  in  setting  a  student  of  the 
Philadelphia  College  of  Pharmacy,  Alfred  Heineberg,  at  work  in 
determining  the  amount  of  resin  in  both  resinous  and  starchy  tubers 
of  jalap,  and  also  in  determining,  among  other  things,  the  difference 
in  specific  gravity  of  the  two  kinds  of  tubers.  The  results  of  this 
work  showed  that  the  starchy  tubers  contained  but  1-76  per  cent, 
of  resin  and  had  an  average  specific  gravity  of  1-194.  The  resin- 
ous tubers  of  jalap  assayed  6-62  per  cent,  of  resin  and  showed  a 
specific  gravity  of  1*360,  and  thus  it  was  demonstrated  that,  in  addi- 
tion to  the  appearance  of  tubers  of  jalap,  a  quick  method  for  deter- 
mining the  value  of  them  lies  in  taking  their  specific  gravity.1 
This  was  subsequently  found  not  to  be  a  new  idea  in  getting  at 
the  valuation  of  tubers  of  jalap.  H.  Hager  ("  Proc.  A.  Ph.  A.,"  1 893, 
p.  120)  prepares  a  solution  of  common  salt  (having  a  specific  gravity 
of  1-140  to  1-142)  by  dissolving  200  grammes  of  table  salt  in  1,055 
grammes  of  water.  The  mixture  is  brought  to  a  temperature  ot 
about  I5°-I7°  C,  and  about  fifty  tubers  are  then  immersed  in  this 
liquid.  Not  less  than  forty-five  out  of  fifty  tubers  should  sink  in 
the  liquid,  and  all  that  do  not  sink  should  be  rejected,  since  good 
tubers  have  a  specific  gravity  between  1-150  and  1-180.  After  ex- 
amination, the  tubers  are  put  into  a  sieve,  washed  off  with  water 
and  dried  with  a  linen  cloth.  Dr.  Hager  furthermore  thinks  that 
the  specific  gravity  of  the  salt  solution  might  be  increased  to  1-150. 
It  is  rather  interesting  that  the  results  of  experiments  carried  on  by 
Mr.  Heineberg  and  those  of  Dr.  Hager  should  so  closely  agree. 
1  The  tubers  should  be  brokeu  in  pieces  before  takiug  their  specific  gravity. 
