226 
Terebene. 
A.m.  Jour.  Pharm. 
May,  1894. 
Some  grades  of  undoubtedly  pure  oil  of  turpentine  show  very  low 
gravities. 
Recently  a  shipment  of  oil  of  turpentine  was  received,  having  a 
gravity  of  only  0-855,  yet  was  without  doubt  pure,  tests  failing  to 
show  any  adulteration. 
A  large  quantity  of  this  oil  was  treated  as  usual,  with  small  quan- 
tities of  sulphuric  acid  in  successive  portions,  samples  being  taken 
after  each  addition.  The  following  table  gives  the  results  of  each 
test,  and  clearly  shows  how  the  gravity  falls  and  the  boiling-point 
rises  as  the  product  becomes  more  inactive.  The  first  column  shows 
the  gravity  of  the  mixture  of  terebene,  colophene,  etc.,  before  distill- 
ing with  steam. 
Gravity 
bef  re 
distilling. 
Gravity 
after 
distilling. 
Rotation 
for 
10  cm. 
1600 
165° 
Percentage  distilling  to 
1700  1750 1800 1850  1900  1950 
200° 
Original  turpentine  .  .  . 
086 
0-855 
IQ°45' 
38 
76 
84 
88 
90 
92 
94 
After  first  acid  .... 
088 
0852 
90  42/ 
IS 
64 
80 
85 
88 
90 
93 
After  second  acid  .  .  . 
090 
0-843 
50  52/ 
IO 
46 
70 
80 
86 
92 
After  third  acid  .... 
092 
0-840 
2°  7' 
6 
45 
68 
80 
85 
88 
93 
After  fourth  acid    .  .  . 
0-93 
0-840 
o°i6' 
2 
33 
60 
75 
84 
87 
92 
After  fifth  acid  .... 
094 
O.835 
o°  4' 
8 
46 
68 
78 
82 
86 
89 
The  crude  terebene  so  obtained  was  then  distilled  to  remove  the 
higher  boiling  portions. 
Examinations  of  commercial  terebenes  show  that  many  of  them 
contain  a  large  percentage  of  oil  of  turpentine,  yet  they  appear  to 
be  satisfactory  to  the  medical  profession. 
If  a  terebene  containing  a  small  amount  of  turpentine  gives  sat- 
isfactory results,  it  appears  useless  to  prepare  a  perfectly  inactive 
article,  for  the  yield  is  then  very  small  and  the  cost  of  production 
correspondingly  high.  A  terebene  containing  only  3  per  cent,  of 
turpentine,  on  being  treated  to  render  it  inactive,  showed  a  loss  of 
50  per  cent. 
Recent  investigation  has  shown  that  the  solvent  action  of  Rochelle 
Salt,  as  shown  on  the  hydrates  of  iron  and  copper,  also  exerts  itself 
on  the  hydrates  of  zinc,  manganese,  nickel,  cobalt,  chromium  and 
aluminum.    (Chem.  News,  69,  125.) 
