392  ACTION  OF  ALKALINE  CHLORIDES  ON  CALOMEL. 
has  occupied  the  attention  of  some  few  of  the  profession  for  a 
considerable  length  of  time,  dating,  perhaps  from  the  year  1763, 
"  when  Capallo  first  observed  the  danger  arising  from  a  mixture 
of  calomel  and  sal-ammoniac." 
Among  those  of  modern  date  who  assert  that  this  change 
does  take  place,  is  found  the  name  of  Koffer,  a  German,  who 
holds  that  he  has  been  able  to  detect  the  alteration,  and  even 
more  prominent,  confirming  his  opinion,  that  of  M.  Mialhe,  who 
communicated  through  the  Journal  de  Pharmacie  for  February, 
1840,  experiments  and  results  verifying  his  assertion.  These 
experiments  were  conducted  in  the  following  manner :  1.  1000 
parts  of  distilled  water,  60  of  common  salt,  60  of  sal-ammoniac, 
and  60  of  calomel  (prepared  by  sublimation,)  which  had  been 
perfectly  washed,  were  mixed  and  allowed  to  react  for  twenty- 
four  hours,  the  temperature  varying  from  68°  to  77°  Fahrenheit ; 
there  was  produced  0-6  of  a  part  of  corrosive  sublimate.  Similar 
experiments  were  made  with  calomel,  prepared  by  precipitation 
with  precisely  similar  results.  2,  1000  parts  of  the  assay  liquor 
(the  alkaline  chlorides  just  enumerated)  had  60  parts  of  calomel, 
{a  la  vapeur)  digested  in  it  for  twenty-four  hours,  at  a  tempera- 
ture varying  from  104°  to  128°  Fahr.,  and  1-5  of  corrosive  sub- 
limate was  produced. 
A  majority  of  medical  practitioners  rely  upon  the  opinion  of 
these  gentlemen,  in  refusing  to  employ  these  substances  in  con- 
junction, and  the  authors  of  the  different  tables  of  incompatibles 
endorse  their  statement  by  directing  that  they  ought  not  to  be 
united  in  prescription. 
Opposed  to  popular  belief  and  the  results  of  the  above  experi- 
ments we  find  that  Dr.  Gardner  denies  the  assertion  of  M. 
Mialhe,  that  calomel  is  converted  into  corrosive  sublimate  by  the 
chlorides  of  the  alkalifiable  metals,  maintaining  that  it  is  merely 
rendered  soluble  by  their  solutions.  Lepage  and  D'Ollegio,  an 
Italian  chemist,  each  from  experiments  made  separately,  also 
contradict  the  opinion  of  M.  Mialhe,  and  hold  :  1.  That  calomel 
when  perfectly  free  from  sublimate,  digested  with  its  own  weight 
of  hydrochlorate  of  ammonia,  or  any  other  alkaline  chloride,  in 
distilled  water,  at  a  temperature  of  from  100°  to  104°  of 
Fahrenheit,  during  twenty-four,  thirty-six  or  even  forty-eight 
hours,  underwent  no  change  of  color.    The  filtered  liquor  did 
