7c6 
Dissolving  Zinc  Chloride. 
Am.  Jour.  Pharm. 
Oct.,  1918. 
C.  Potassium-bismuth  iodide  gave  a  red  precipitate. 
D.  With  dilute  iodic  acid,  iodine  was  at  once  liberated. 
E.  Neutral  calcium  chloride  solution  gave  no  precipitate,  but 
when  made  slightly  alkaline  with  dilute  ammonium  hydroxide  before 
being  added  to  the  morphine  tartrate,  a  white  gelatinous  precipitate 
formed  on  completion  of  the  mixture.  This  precipitate  had  the 
usual  appearance  of  calcium  tartrate. 
The  morphine  tartrate  solution  was  almost  neutral  to  litmus, 
though  distinctly  acid  to  phenolphthalein.  It  is  probably  this  degree 
of  acidity  which  prevents  the  formation  of  calcium  tartrate  in  a  solu- 
tion not  rendered  alkaline  by  ammonium. 
SOME  OBSERVATIONS  ON  THE  DISSOLVING  OF  ZINC 
CHLORIDE  AND  SEVERAL  SUGGESTED 
SOLVENTS.1 
By  Josiah  C.  and  Bertha  L.  DeG.  Peacock. 
The  salts  of  zinc  which  are  soluble  in  water,  especially  the 
sulphate,  acetate  and  chloride,  have  long  been  used  in  injections, 
lotions,  eye-washes,  mouth-washes  and  other  such  forms  of  applica- 
tion, usually  in  weak  solutions,  a  few  grains  to  the  ounce. 
The  sulphate  and  acetate  of  zinc  readily  dissolve  in  water  with- 
out residue ;  but  zinc  chloride  upon  contact  with  water  has  a  strange 
behavior;  and  when  treated  with  water  in  large  proportions  leaves 
an  insoluble  residue  known  as  oxychloride,  or  basic  chloride  of  zinc ; 
it  matters  not  which  is  added  to  the  other.  This  undissolved  por- 
tion is  bulky,  therefore  impressive  as  to  quantity  especially  when 
resulting  from  one  or  two  grains  of  zinc  chloride  intended  for  eye- 
drops. That  it  does  contain  both  zinc  and  chlorine,  we  have  as- 
sured ourselves  by  qualitative  analysis  ;  it  may  therefore  be  rightly 
termed  basic  chloride  of  zinc,  or  oxychloride.  Whatever  of  oxide 
of  zinc  or  oxychloride  of  zinc  was  present  in  the  sample  dissolved 
may  also  be  looked  for  here. 
In  order  to  appreciate  the  quantity  of  oxychloride  usually  left 
undissolved,  let  us  cite  a  reference  found  in  the  proceedings  of  the 
American   Pharmaceutical   Association,    1896,   page    715 — "Zinc 
1  Presented  at  the  meeting  of  the  Pennsylvania  Pharmaceutical  Associa- 
tion, Wilkesbarre,  Pa.,  June,  1918. 
