Am.  Tour.  Pharm. ) 
Dec,  1877.  J 
A  Iter  ability  of  Calomel. 
611 
The  ZnO  is  too  high,  owing  either  to  an  impurity  in  the  salt  or  to  a 
fault  in  the  analysis  ;  but  I  had  not  time  to  examine  into  the  matter. 
The  zinc-salt  crystallized  in  four-sided  truncated  prisms,  which  were 
insoluble  in  alcohol. 
I  am  unable  to  state  from  what  species  of  salix  the  acid  was  prepared 
but  as  all  the  samples  of  bark  I  have  examined  gave  acid  infusions,  it 
is  not  improbable  that  lactic  acid  exists  in  all  the  members  of  the  Sali- 
caceae. — Phar.  Jour,  and  Trans.,  Sept.  22,  1877. 
ON  THE  ALTERABILITY  OF  CALOMEL  AND  THE 
PRECAUTIONS  NECESSARY  IN  ITS  THERAPEUTI- 
CAL EMPLOYMENTS. 
By  M.  Jolly,  Pharmacien. 
Owing  to  the  report  which  appeared  in  the  Italian  pharmaceutical 
papers  on  the  formation  of  corrosive  sublimate  in  a  mixture  of  calo- 
mel and  sugar,  the  president  of  the  Society  of  Practical  Medicine 
engaged  the  author  to  make  some  experiments  to  clear  up  all  doubt  on 
this  subject. 
Calomel  has  a  decided  tendency  to  decompose  into  mercury  and  cor- 
rosive sublimate,  and  many  physical  and  chemical  agents  facilitate  this 
decomposition.  The  author  has  investigated  the  action  of  these  various 
agents,  and  embodies  his  results  in  the  paper  before  us. 
Heat  always  causes  decomposition  to  a  greater  or  less  extent.  Per- 
fectly pure  and  dry  calomel,  sublimed  alone,  takes  a  greyish  tinge  from 
the  liberation  of  metallic  mercury. 
Light  causes  the  change  into  mercury  and  corrosive  sublimate  to 
take  place  rapidly,  as  evidenced  by  the  change  in  color. 
One  gram  of  calomel  digested  with  100  cc.  of  a  2  per  mille  solu- 
tion of  acid  hydrochlor.  for  six  hours,  at  a  temperature  of  1040  Fahr.^ 
yielded  3  milligrams  of  corrosive  sublimate. 
The  same  quantity  digested  with  5  per  mille  solution  of  sodium 
chloride  yielded  at  the  end  of  six  hours  1  milligram  of  sublimate. 
A  2  per  cent,  solution  of  citric  acid  (to  represent  fruit  preserves,  in 
which  calomel  is  often  administered)  caused  the  production  of  one 
milligram  of  sublimate. 
The  hydrochloric  acid  and  sodium  chloride  represent  the  gastric  juice. 
When  calomel  passes  into  the  intestines,  it  comes  in  contact  with  the 
alkaline  secretions  of  the  bowels. 
