Am.  Jour.  Pharm.  \ 
December,  1915.  j 
Progress  in  Applied  Science. 
567 
to  sophisticate  olive  oil.  The  following  method  for  its  detection  is 
suggested :  One  mil  of  the  suspected  oil  is  heated  with  5  mils  of  an 
8  per  cent,  alcoholic  caustic  potash  solution  for  4  minutes  in  a  flask 
provided  with  a  condensing  tube.  After  cooling  to  25 °,  1.5  mils  of 
a  mixture  of  one  volume  of  glacial  acetic  acid  and  two  volumes  of 
water  are  added,  followed  by  50  mils  of  70  per  cent,  alcohol.  If  the 
solution  is  turbid,  it  is  carefully  heated  until  perfectly  limpid,  is  then 
cooled  gradually,  and  the  temperature  at  which  it  becomes  turbid  is 
noted.  Pure  olive  oil  becomes  turbid  at  13.50  ;  that  containing  5 
per  cent,  arachis  oil  becomes  turbid  at  16.90 ;  that  containing  10  per 
cent,  becomes  turbid  at  19.80,  and  so  on.  The  higher  the  percentage 
of  arachis  oil  present,  the  higher  the  temperature  at  which  the  sus- 
pected oil  becomes  turbid.    {The  Druggists'  Circular,  October,  191 5, 
P.  665.) 
Some  Ash  Determinations  on  Digitalis. — Some  commercial 
digitalis,  as  well  as  some  digitalis  grown  under  their  own  super- 
vision, was  examined  for  ash  residue.  The  results  obtained  seem 
to  justify  the  writers  in  making  the  statement  that  a  pharmacopceial 
requirement  of  10  per  cent,  ash  would  exclude  some  specimens  that 
would  be  authentic  and  of  good  quality.  (By  E.  L.  Newcomb  and 
M.  H.  Haynes,  The  Druggists'  Circular,  November,  191 5,  p.  739.) 
PROGRESS  IN  APPLIED  SCIENCE. 
New  Method  of  Making  Sulphuric  Acid. 
A  new  method  of  manufacturing  sulphuric  acid,  for  which  advan- 
tages are  claimed,  is  suggested  in  United  States  Department  of 
Agriculture  Bulletin  No.  283,  "  The  Production  of  Sulphuric  Acid 
and  a  Proposed  New  Method  of  Manufacture."  The  essential  dif- 
ference of  the  method  is  that  the  gases  employed  are  drawn  down- 
ward through  a  spiral  flue  in  place  of  being  drawn  through  lead 
chambers  or  intermediate  towers.  It  is  asserted  that  the  resistance 
of  gases  to  the  downward  pull  and  the  constant  change  in  their 
course  through  the  spiral  tend  to  mix  them  very  intimately.  The 
fact  that  the  gases  constantly  impinge  on  the  walls  of  the  spiral 
flue,  which  can  be  cooled  either  by  air  or  water,  makes  it  practicable 
to  maintain  the  gases  at  a  temperature  most  favorable  for  the  effi- 
cient yield  of  sulphuric  acid. 
In  laboratory  tests  in  which  the  spiral  was  utilized,  practically  all 
