SULPHATE  OF  LIME,  ETC. 
207 
SULPHATE  OF  LIME  AN  IMPURITY  IN   TINCTURE  OF 
CHLORIDE  OF  IRON. 
By  Ur.  Robert  Battey. 
To  the  Editor  offlie  American  Journal  of  Pharmacy. 
Dear  /Sir, — In  the  March  number  of  your  Journal  J.  C. 
Wharton  comments  upon  certain  "  silky  white  needles,  of  a  lustre 
something  like  asbestos,"  which  he  has  observed  to  slowly  crys- 
tallize down  from  muriated  tincture  of  iron,  and  suggests  the 
opinion  that  it  is  dissolved  off  from  the  glass  vessel  used,  and 
also  the  inquiry  if  it  be  not  silicate  of  lime. 
I  have  several  times  observed  the  same  long,  slender  and  deli- 
cate needles,  in  color  and  lustre  just  such  as  he  describes,  and 
have  likewise  observed  the* following  facts  ; 
1st.  It  is  only  occasionally  that  my  tincture  of  iron  deposits 
these  crystals,  whilst  it  always  deposits  more  or  less  of  the 
yellowish  precipitate  he  mentions. 
2d.  A  given  sample  of  muriatic  acid,  which  has  been  used 
when  the  crystals  have  formed,  will  uniformly  cause  their  depo- 
sition. 
3d.  That  the  crystals  themselves,  when  carefully  washed  and 
tested  both  in  the  wet  way  and  before  the  blow-pipe,  give  the 
characteristic  reactions  of  sulphate  of  lime. 
My  opinion  is  that  these  crystals  are  only  a  trace  of  sulphate 
of  lime,  introduced  as  an  impurity  in  some  samples  of  commer- 
cial muriatic  acid,  and  have  no  necessary  connection  with  the 
yellowish  deposit. 
Eome,  G-a.,  21st  March,  1870. 
PHARMACEUTICAL  NOTICES. 
Editor  of  the  American  Jour.  Pharmacy  : 
Dear  Sir, — Tne  following  may  perhaps  interest  some  of  the 
readers  of  the  Journal : 
Aqua  Chlorinii  Extemp, 
Put  in  a  bottle  potass,  chlorat.  40  grains ;  add  muriatic  acid, 
C.  P.,  J  oz.  troy.  When  the'  bottle  begins  to  get  filled  with 
chlorine-vapors  add  dist.  water  one  fluid-ounce.    Stopper  the 
