ACTION  OF  VEGETABLE  ACIDS  ON  CALOMEL. 
527 
of  the  solar  rays,  rather  than  to  a  special  action  of  the  light  ; 
but  it  was  not  difficult  to  ascertain  that  this  heat  alone  would  not 
have  produced  the  phenomenon,  especially  in  so  short  a  time  ;  a 
solution  of  iodine  in  oil,  which  was  kept  for  four  hours  at  a  tem- 
perature of  32°  C.  (89°  6'  F.),  had  lost  none  of  its  red  color. 
It  sometimes  happens  that  iodised  oil  will  resume  its  red  color, 
when  kept  in  the  dark  or  in  diffused  light ;  but  a  fresh  exposure 
to  direct  light  decolors  it  again  very  quickly — London  Chemist, 
from  Journal  de  Pharmacie  et  de  Chimie. 
ON  THE  ACTION  OF  THE  VEGETABLE  ACIDS  ON  CALOMEL. 
By  M.  Bauwens.' 
The  most  enlightened  physicians,  the  greatest  chemists,  and 
most  prudent  pharmaceutists,  on  the  faith  of  tradition,  always 
advise  patients  not  to  take  any  acid  substances  when  calomel 
has  been  administered  to  them.  M.  Bauwens  has  made  some  in- 
vestigations on  this  subject,  and  has  obtained  the  following  results. 
At  the  ordinary  temperature,  at  86°,  and  even  104°  F.  (30° 
and  40°  C.)  calomel,  in  prolonged  contact  with  a  concentrated 
solution  of  tartaric  or  citric  acid,  gave  no  trace  of  corrosive  sub- 
limate. 
Calomel,  which  is  insoluble  in  water,  alcohol  and  ether  does 
not  instantly  communicate  to  the  tongue  the  styptic  flavor  of 
the  soluble  preparations  of  mercury;  but  this  taste  is  perceived 
when  the  alkaline  haloid  salts  of  the  saliva  come  in  contact  with 
it,  in  consequence  of  the  property  possessed  by  alkaline  salts 
of  dissolving  the  mineral  haloid  salts  to  form  double  salts  with  them. 
Calomel  appears  to  owe  its  anthelmintic  and  purgative  pro- 
perties to  the  haloid  salts  which  it  finds  in  the  economy.  If 
large  doses  of  calomel  act  relatively  less  powerful  than  small 
ones,  it  is  because  in  the  first  case  the  mercurial  salt  does  not 
find  in  the  economy  a  sufficiency  of  alkaline  salt  to  convert  it  all 
into  soluble  salt;  whereas,  in  the  second  case  there  are  sufficient 
alkaline  salts  in  the  intestinal  canal  to  dissolve  the  mercurial  salt 
completely.  Consequently  children  who  seldom  take  much  chlo- 
ride of  sodium,  can  take  more  calomel  in  proportion  than  grown 
people.  The  physicians  of  sea-side  towns,  where  the  water  is 
brackish,  seldom  prescribe  calomel,  and  the  doctors  of  the  fleet 
have  been  obliged  to  abstain  from  giving  it  to  sailors  who  eat 
salt  meat. 
