562  Lime  Water  and  Compressed  Lime  Tablets ■.{A™ovembe?.hi89s?" 
wintergreen  deviates  the  ray  of  polarized  light  —  o°  25',  in  an  100 
millimetre  tube, 
The  results,  as  parallelled  in  the  foregoing  chart,  show  that  Power 
and  Kleber's  conclusions  in  1895  are  much  nearer  Trimble  and 
Schroeter's  of  1 889  than  they  are  to  those  of  Power  in  that  same  year. 
The  additional  compounds  separated  from  the  hydrocarbons  of 
these  oils  by  Power  and  Kleber  in  no  way  reflect  on  the  work  of 
Mr.  Schroeter  and  myself,  since  we  first  pointed  out  the  fact  that 
these  hydrocarbons  separated  into  a  solid  and  liquid  portion,  and,  in 
the  face  of  figures  obtained  by  us  for  a  sesquiterpene,  we  made  a  res- 
ervation and  predicted  that  a  further  investigation,  which  we  could 
not  make  at  that  time,  would  show  these  hydrocarbons  to  be  made 
up  "  of  two  or  even  more  compounds."  So  far  as  the  results  of 
Power  and  Kleber,  concerning  these  hydrocarbons,  are  new,  I  accept 
them  until  such  a  time  as  I  can  further  study  these  oils. 
The  only  vital  question  at  issue  now  is  concerning  the  presence  or 
absence  of  benzoic  acid  and  ethyl  alcohol  in  these  oils.  Power  and 
Kleber  have  apparently  not  tried  the  method  employed  by  Trimble 
and  Schroeter  for  the  separation  and  detection  of  benzoic  acid;  they 
simply  declare  it  absent  because  the  acid  which  they  separated  from 
the  oils  "melted  at  precisely  1 5 5*5 0  C,"  and,  I  may  add,  at  least  one- 
half  of  a  degree  below  the  generally  accepted  melting  point  of  pure 
salicylic  acid. 
The  secret  process  of  rectifying  these  oils,  referred  to  by  Power 
and  Kleber,  is  not  one  of  distillation,  as  presumed  by  them,  but 
simply  filtration  through  absorbent  cotton ;  at  least,  that  is  the 
practice  at  a  number  of  distilleries  visited  by  me. 
AN   EXAMINATION  OF  LIME  WATER  AND  COM- 
PRESSED LIME  TABLETS. 
By  David  L.  Greenawai/t,  Ph.G. 
Contribution  from  the  Chemical  Laboratory  of  the  Philadelphia  College  of 
Pharmacy.    No.  149. 
To  ascertain  the  quality  of  lime  water  as  ordinarily  dispensed, 
samples  were  obtained  from  retail  drugstores  located  in  Philadelphia 
and  some  neighboring  cities  and  towns.  These  samples  were  ex- 
amined in  such  manner  as  would  decide  whether  they  conformed  to 
the  following  requirements,  which  the  United  States  Pharmacopoeia 
gives  for  lime  water : 
