Minim  Pipettes. 
(  Am.  Jour.  Pharm. 
(      June,  1879. 
oil  of  oranges.  Wenzell  contrasts  its  characters  with  those  of  tere- 
bene  from  P.  Sylvestris.  Abietene,  sp.  gr.  0-694,  boils  at  1010,  dis- 
solves but  a  small  quantity  of  hydrochloric  acid  gas,  and  is  but  little 
attacked  by  cold  nitric  acid,  Terebene,  sp.  gr.  0  840,  boils  at  160% 
absorbs  HC1  with  avidity,  and  is  violently  attacked  by  nitric  acid.  From 
a  consideration  of  the  general  properties  and  behavior  of  this  hydro- 
carbon the  author  of  the  present  paper  concluded  that  it  was  likely  to 
be  a  paraffin.  The  occurrence  of  a  paraffin  playing  the  part  of  oil  of 
turpentine  in  the  vegetable  kingdom  was.  hitherto  unheard  of,  the  only 
natural  sources  of  this  hydrocarbon  (heptane)  being  petroleum  and  fos- 
sil fish-oil.  The  author,  therefore,  obtained  from  Mr.  Wenzell  two 
gallons  of  the  abietene,  and  has  subjected  it  to  a  most  exhaustive  chem- 
ical and  physical  examination,  the  details  of  which  are  contained  in  the 
paper.  The  crude  oil  is  slightly  contaminated  with  a  resinoid  matter* 
to  which  its  smell  is  due.  The  pure  oil  boils  at  98*42°C.  at  760  mm. 
It  has  the  composition  of  heptane,  containing  83  85  per  cent.  C,  16*03 
per  cent.  H  (C7H16  requires  C  83  97,  and  H  16*03).  Vapor  density — 
found,  49*94  ;  calculated,  50*07  ;  sp.  gr.  at  o°  0*70057.  The  rate  of 
expansion  by  heat  has  been  carefully  determined  ;  its  volume  at  the 
boiling-point  is  1*1411.  Its  specific  volume  162*54;  refractive  index 
for  D,  1*3879  ;  its  molecular  refractive  energy,  56*4.  Rotates  in  a 
tube  200  mm.  -{-6*9'.  Its  viscosity  and  surface  tension  were  also 
determined.  The  author  has  compared  the  heptane  obtained  from  P. 
Sabiana  with  the  heptane  from  petroleum  and  that  obtained  by  heating, 
azelaic  acid  with  baryta.  The  sp.  gr.  of  the  heptane  from  petroleum 
is  0*7301  ;  that  from  azelaic  acid  has  a  sp.  gr.  of  0*700  These  hep- 
tanes are  believed  by  Schorlemmer  to  be  identical.  The  author  is  at 
present  engaged  in  an  investigation  of  this  point. 
MINIM  PIPETTES. 
By  E.  R.  Squibb,  of  Brooklyn. 
In  the  last  number  of  the  "Journal"  Mr.  Drew  controverts  the 
statements  of  this  writer  in  the  preceding  number  by  skillfully  dividing, 
the  subject  of  the  devices  for  minim  pipettes,  and  claiming  only  that 
which  he  figured.  This  subject  would  not  be  at  all  worth  discussing 
for  itself  alone,  or  for  any  credit  involved.  But  as  there  is  a  moral 
principle  involved,  it  seems  necessary  for  this  writer  to  say  again,  more 
