"^""noT'is^o!'"'}  Stability  of  Calomel  539. 
reaction  with  stannous  chloride,  indicative  of  the  presence  of  corrosive 
sublimate,  though  not  so  marked  as  in  the  two  preceding  experiments. 
8.  Calomel  and  dilute  hydrochloric  acid  were  treated,  at  gS^F.,  in 
same  manner,  and  after  one  hour  a  very  distinct  grayish  coloration  was 
had  with  stannous  chloride.     The  same  occurred  with  citric  acid. 
Summary. —  Experiment  7  "  shows  that  calomel^  at  the  temperature 
of  the  body  (98°),  is  slowly  converted  into  corrosive  sublimate.  Experi- 
ments "5,"  "6"  and  "8"  show  that  chloride  of  sodium,  chloride  of 
ammonium,  hydrochloric  and  citric  acids  further  this  change  of  calomel 
into  the  poisonous  chloride,  and  are  hence  more  or  less  dangerous  when 
existing  in  the  system  wirh  calomel.  The  result  of  the  above  eight 
experiments  would  seem  to  indicate  that  the  different  temperatures  at 
which  the  experiments  are  conducted  will  explain  in  part  the  dis- 
screpancies  on  this  subject.  The  experiments  further  show  that  at  the 
temperature  of  the  body  calomel  is  an  unstable  compound. 
The  question  of  the  conversion  of  calomel  into  corrosive  sublimate 
by  sugar,  magnesia,  bicarbonate  of  sodium  and  carbonate  of  magnesium 
was  next  taken  up  and  the  following  experiments  performed  : 
A.  Calomel  and  sugar  were  rubbed  together,  and  after  twenty-four 
hours  a  test  for  corrosive  sublimate  failed  to  indicate  its  presence,  and 
no  trace  of  the  poisonous  compound  could  be  discovered  in  the 
powders,  even  after  fifteen  days. 
B.  Calomel  and  magnesia,  treated  in  same  manner,  gave  evidence  of 
corrosive  sublimate  after  twenty-four  hours. 
C.  Calomel  and  carbonate  of  magnesium  gave  same  results  as  in 
experiment  "  B,"  as  did  also  calomel  and  bicarbonate  of  sodium. 
The  results  of  these  experiments,  except  "A,"  agree  with  the  asser- 
tion of  G.  Velpins  (loc.  cit.). 
These  two  sets  of  experiments  would  seem  to  prove  that  M.  Verne's 
conclusions  are  not  altogether  correct ;  that  temperature  is  a  great  factor 
in  considering  the  question  of  the  stability  of  calomel  ;  that  M.  Berthe's 
statement  (loc.  cit.)  in  regard  to  the  conversion  of  calomel  into  cor- 
rosive sublimate  at  high  temperatures  is  correct,  and  prove  also  the 
correctness  of  M.  Mialhe's  assertion  that  the  alkaline  chlorides  increase 
the  activity  of  calomel. 
Newcomersto-ivn^  Ohio^  October  ii,  1880. 
