i78 
Arts  to  I. 
Am.  Jour.  Pliarm. 
April,  1891. 
made  with  sodium  carbonate  yielded  -777  grin,  silver  iodide  corre- 
sponding to  41-98  per  cent,  of  iodine.  Heating  -2  grm.  in  a  sealed 
tube  with  silver  nitrate  and  nitric  acid  (Carius'  method)  -155 
grm.  silver  iodide  was  obtained  corresponding  to  41-87  per  cent,  of 
iodine. 
On  repeating  the  experiments  of  Messinger  and  Prckersgill  {Ber. 
23,  p.  2761,  see  Jour.  Chem.  Soc ,  1890,  1403)  and  reducing  aristol 
by  dissolving  in  ether  and  adding  solution  of  potassium  hydrate  in 
alcohol  and  then  zinc  dust  gradually  in  small  quantities  and  boiling 
on  the  water-bath  in  a  reflux  apparatus,  and  finally  boiling  off  the 
alcohol,  maintaining  the  bulk  of  the  liquid  by  the  addition  of  water  ; 
the  liquid  thus  obtained  was  filtered  from  the  excess  of  zinc,  acidu- 
lated with  sulphuric  acid,  and  extracted  with  ether.  The  product 
was  purified  by  redissolving  in  alcohol,  and  yielded  a  compound 
possessing  a  peculiar  odor  of  thymol  almost  phenol-like.  It  gave 
no  reaction  with  ferric  chloride,  and  although  impure  corresponded 
fairly  well  with  the  properties  assigned  to  dithymol. 
Dithymol  was  first  obtained  by  Dianin  (see  Jour  Chem.  Society, 
1882,  130),  by  treating  thymol  with  neutral  ferric  chloride  or  sul- 
phate or  ferric  alum,  the  reaction  being  represented  by  the  equation 
2C10HuO  -f  Fe2(S04)3  =  C20H26O2  +  2FeS04  +  H2S04 
The  relation  between  thymol  and  dithymol  is  graphically  repre- 
sented by 
CR 
// 
HC 
CH 
CH9 
CH, 
C 
HC 
-C 
c 
HC  COH 
Wc/ 
C3H7 
Thymol. 
HC       COH.HOC  C 
Wc/  ^c// 
C3H7 
C3H7 
Dithymol. 
Goldman  (loc.  cit )  states  that  aristol  is  di-iodo-dithymol  C^H^O^, 
containing  45 -8  per  cent,  of  iodine.  Accepting  his  formula,  there 
should  be,  by  calculation,  46- 15  per  cent,  of  iodine.  But  the  manu- 
facturers drying  the  product  at  a  low  temperature  to  prevent  decom- 
position, there  must  be  some  water  retained,  and  the  loss  on  heat- 
