Turpen  tine.  r  Am- Jour- Pharm- 
(       June,  1890. 
different  proportions  of  petroleum  (sp.  gr.  at  150  C,  0786;  boiling 
point  between  1500  C.and  1600  C. ;  known  as  head  light  oil),  it  was 
found  that  as  much  as  65  per  cent,  of  petroleum  could  be  mixed 
without  detecting  it  by  the  above  test. 
Absolute  glacial  acetic  acid,  99-5  to  100  per  cent,  was  tried  and 
found  to  mix  in  all  proportions  with  petroleum  as  well  as  with 
turpentine  oil. 
A  mixture  of  99  cc.  absolute  glacial  acetic  acid  with  1  cc.  of 
water  when  mixed  with  turpentine  oil  in  the  proportion  of  one  to 
one  formed  a  clear  mixture,  but  with  petroleum  in  the  same  pro- 
portions it  would  not  mix.  Mixtures  of  petroleum  and  turpentine 
oil  in  different  proportions  were  found  to  require  different  amounts 
of  the  above  acid  for  making  a  clear  solution,  as  follows: 
Petroleum,   1        2        3  4  5  7  8  cc. 
Turpentine  oil,  ...  9  8  7  6  5  3  2  cc. 
Glacial  acid,  ....   40       60       So       no       150       230       270  cc. 
The  crude  "  gum  "  was  found  to  be  dissolved  by  absolute  alcohol, 
ether,  glacial  acetic  acid,  slightly  by  70  per  cent,  alcohol,  and  not 
at  all  by  water. 
On  treating  100  grams  of  the  original  "  gum  "  with  petroleum 
ether  boiling  between  25 0  and  45 0  C.  there  was  dissolved  81  per 
cent,  of  it ;  and  by  setting  the  solution  aside,  clear  stellate  crystals 
commenced  to  deposit  in  less  than  a  week,  and  in  two  or  three 
months  about  20  to  25  per  cent,  of  the  solution  had  crystallized  in  the 
same  form.  The  19  per  cent,  of  insoluble  matter  was  treated  with 
stronger  ether  which  dissolved  it  completely ;  the  solution  was  set 
aside  and  crystals  deposited  on  the  bottom  and  sides  of  the  beaker 
after  long  standing ;  as  in  the  previous  solution  none  formed  at  the 
surface. 
Another  100  grams  of  the  original  "  gum  "  were  treated  with 
petroleum  ether  boiling  between  45  and  75 0  C,  which  dissolved 
97  per  cent.;  the  solution  was  filtered  and  on  standing,  gradually 
deposited  crystals  in  the  same  manner  and  similar  in  appearance  to 
those  from  light  petroleum  ether. 
The  3  per  cent  of  the  "  gum  "  which  was  insoluble  was  dissolved 
in  stronger  ether,  and  upon  spontaneous  evaporation  of  the  ether 
a  resinous  mass  was  left. 
The  crystals  that  were  gotten  from  the  different  petroleum  ethers 
