Am.  Jour.  Pharrn. ) 
Oct.,  1892.  / 
Assay  of  Jalap. 
533 
apertures  through  which  pass  air-tight,  respectively,  the  pear-shaped 
bulb,  a  thermometer,  a  thermostat,  and  a  long  tube  open  at 
both  ends  to  condense  any  mercury  vapor.  A  tube  connects  the 
pear-shaped  bulb  with  a  Hofmann's  burette,  in  which  the  hydrogen 
is  measured. 
The  author's  process  is,  however,  more  particularly  directed  to  the 
estimation  of  the  paraffins.  After  three  hours,  when  no  more  gas 
will  be  given  off,  the  residue  is  powdered,  and  to  prevent  any  loss 
the  bulb-tube  is  also  broken  up,  and  the  whole  is  extracted  with 
light  petroleum  in  a  Soxhlet's  apparatus.  The  petroleum  is  distilled 
off,  and  the  residual  paraffin  dried  at  I  io°  and  weighed.  On  apply- 
ing the  process  to  yellow  beeswax  of  undoubtedly  genuine  origin, 
the  amount  of  natural  hydrocarbons  was  found  to  vary  from  1 1 -02  to 
14-7  per  cent.,  although  in  practice  the  average  amount  may  be  put 
down  as  13-5  per  cent. 
A  sample  of  Transylvanian  wax,  tested  by  the  author,  had  an 
acidity  equivalent  of  1 6* 66,  and  a  true  saponification  number  of 
56-02,  which  pointed  to  adulteration  with  paraffin,  or  a  similar  sub- 
stance. Analyzed  by  the  author's  method,  the  percentage  of  hydro- 
carbons came,  indeed,  to  28*12,  corresponding  with  17  per  cent,  of 
adulteration,  calculated  on  the  original  sample.  A  sample  of  wax, 
which  had  been  purposely  adulterated  with  8  per  cent,  of  paraffin, 
showed  on  analysis  7-4  per  cent. 
The  amount  of  hydrocarbons  in  samples  of  white  wax  varied  from 
10-93  to  15-48  per  cent.,  but  the  purity  of  some  of  the  samples  was 
rather  doubtful. 
THE  ASSAY  OF  JALAP. 
By  F.  H.  Alcock,  F.I.C. 
Numerous  papers  have  appeared  in  the  Journal  from  time  to  time 
on  the  subject  of  jalap  and  matters  connected  with  it. 
It  is  not,  however,  so  much  upon  the  quality  of  the  drug  and 
amount  of  resin  which  it  contains  that  I  wish  to  deal  in  this  note  as 
to  give  an  easy  method  of  ascertaining  the  quantity  of  resin  in  the 
drug  or  its  preparations. 
The  official  process  and  its  many  modifications  do  not  appear  to 
give  entire  satisfaction,  and  the  conclusion  I  have  come  to  after 
many  trials  is  that  the  following  process  may  prove  to  be  in  several 
ways  more  acceptable  to  pharmacists.    It  depends  upon  the  great 
