Am.  Jour.  Pharm. 
April,  1891. 
Aristol. 
177 
statement  which  is  confirmed  by  my  experiments.  Dr.  F.  Goldman 
{Apotk.  Zeit.y  1890,45;  also,  Amer.  Journ.  of  Pharmacy,  1890,  129) 
states  that  aristol  or  di-iodo-dithymol  is  made  by  the  action  of  a  solu- 
tion of  iodine  in  potassium  iodide  upon  a  solution  of  thymol  in 
sodium  hydrate.  The  same  statement  is  made  by  Dr.  EichhofT 
{Pharm.  Journ.  and  Trans.,  1890,  Febr.,  page  601). 
The  writer  could  find  no  published  chemical  examination  of  the 
commercial  aristol,  and  several  other  iodine  compounds  with  thymol 
are  possible.  And,  as  the  precipitate  obtained  by  adding  iodine  in 
potassium  iodide  solution  to  an  alkaline  thymate  solution  was  so 
different,  it  became  necessary  to  make  some  examination  of  the 
article  supplied  under  that  name  before  answering  the  first  part  of 
this  query. 
An  original  package  of  that  supplied  by  the  "  Farben  Fabriken  " 
Company  of  Elberfeld  was  obtained,  and  upon  examination  showed 
the  following  characteristics  :  a  pale  yellowish  red  amorphous  pow- 
der, easily  soluble  in  ether,  chloroform,  benzene  and  petroleum 
ether,  and  less  soluble  in  alcohol.  It  was  insoluble  in  water,  but 
yielded  to  that  liquid  a  slight  trace  of  chloride.  Heating  it  on  the 
water  bath  it  became  lighter  in  color  and  at  65 0  C.  it  gave  off  suffi- 
cient iodine  vapors  to  blue  a  piece  of  filter  paper  moistened  with 
starch  solution.  On  heating  at  100°  C.  for  4  hours  it  lost  64  per 
cent,  and  after  6  hours  7-4  per  cent.  It  darkens  at  1240  to  1260  C, 
shrivels  into  a  dark  mass  at  1340  to  1360  C.  and  fuses  at  1 5 8 0  C, 
and  yielded  on  incineration,  nearly  one  per  cent,  of  ash,  which 
reacted  for  sodium  chloride. 
1  grm.  intimately  mixed  with  pure  calcium  oxide,  and  a  combus- 
tion made  thereof,  yielded,  upon  precipitation,  -745  grm.  silver 
iodide,  corresponding  to  40-25  percent,  of  iodine.    A  combustion 
brown  flocculent  precipitate  whereby  for  1  molecule  thymol  used  4  atoms  of 
iodine  are  required.    The  used  quantity  of  iodine  is  X  1^*t  ^„  =  o'2<)56jj2. 
506*16 
Process  o-i  to  0*3  grm.  thymol  is  dissolved  in  NaHO  (4  mols.  for  each  mole- 
cule of  thymol)  treated  with  —  iodine  solution.    The  solution  acidified  and 
10 
the  remaining  iodine  determined  as  in  the  phenol  investigation. 
y9-naphthol  gives  under  similar  conditions  a  dirty  green  precipitate,  and  is 
determined  by  the  same  method.  The  factor  is  likely  I4^  66  0*37843106. 
37962 
The  alkali  used  must  be  nitrite  free/ —  Chem.  Zeitung,  1890, page  291. 
