Am'juiyf i9OT. rm* }     The  Influence  of  Oxygen  on  Olive  Oil.  309 
the  iodine  number  as  ranging  between  79-91*5  (mostly  83),  and 
the  saponification  number  as  ranging  between  188- 196.  Bujard  and 
Baier1  give  the  iodine  number  as  ranging  mostly  between  79-85, 
although  it  has  been  found  to  be  as  high  as  90,  and  the  saponifica- 
tion number  as  ranging  between  1 85-196. 
The  olive  oil  employed  in  our  experiments  was  a  new  oil  of  first 
quality  obtained  as  a  direct  importation  by  us  from  the  maker  in 
Sancasciano,  Val  di  Pesa,  Italy.  It  was  of  a  light  amber  color, 
slightly  tinted  green,  and  its  flavor  was  that  of  a  sweet  olive  oil. 
The  index  of  refraction  corresponded  to  that  of  a  pure  olive  oil. 
Pasteur  pipette  flasks  were  employed  to  contain  the  oil  in  the 
experiments.  All  of  the  flasks  were  identical  in  capacity  (100  ex.) 
and  the  amount  of  oil  used  in  each  flask  was  20  c.c.  The  gases 
were  passed  through  the  flasks  until  all  the  air  was  displaced  as 
determined  in  the  case  of  filling  the  flask  with  oxygen  by  collecting 
some  of  the  gas  issuing  from  the  escape  tube  of  the  flask  and  observ- 
ing whether  it  was  completely  absorbed  by  an  alkaline  solution  of 
pyrogallol ;  and  in  the  case  of  nitrogen  by  observing  whether  an 
alkaline  solution  of  pyrogallol  was  no  longer  discolored  by  the  issuing 
gas.  In  this  procedure  the  end  of  the  exit  tube  of  the  flask  was 
made  to  dip  below  the  surface  of  water  which  served  the  purpose  of  a 
seal.  When  the  flask  was  filled  with  the  desired  gas  both  tubes  of  the 
flask  were  sealed  by  means  of  a  blowpipe  flame.  In  the  cases  where 
sterilization  was  effected  the  flask,  with  both  tubes  plugged  with 
sterilized  absorbent  cotton,  was  immersed  in  boiling  water  for  fifteen 
minutes  at  a  time  on  three  consecutive  days  before  passing  gas  into 
it.  Oxygen  was  obtained  by  heating  pure  potassium  chlorate. 
Before  conducting  the  gas  into  the  flask  it  was  passed  through  a 
solution  of  sodium  hydroxide  and  then  through  a  tube  containing 
sterilized  absorbent  cotton.  Nitrogen  was  obtained  by  heating  a 
solution  of  ammonium  chloride  and  potassium  nitrite.  The  gas 
thus  obtained  was  passed  consecutively  through  solutions  of  ferrous 
sulphate,  sodium  hydroxide  and  alkaline  solution  of  pyrogallol  and 
then  through  a  tube  containing  sterilized  absorbent  cotton  before 
it  was  conducted  into  the  flask. 
Determinations  of  the  iodine  number  (Hiibl)  and  of  the  saponifi- 
1  Bujard  und  Baier,  Hilfsbuch  f.  Nahrungsmittelchemiker.  Jul.  Springer, 
1900,  p.  101. 
