310 
GLEA  NINGS — PHARMACE  UTIC AL,  ETC. 
No.  5,  was  obtained  of  a  New  York  importer  about  fifteen 
years  ago,  by  a  wholesale  druggist  of  this  city. 
Mat.  insoluble  in  HC1  chiefly  .  BaO  S03  48.50 
Sesquioxide  of  Iron,  .  .  .  Fe203  2.00 
Carbonate  of  Lime,      .       .       .       CaO  C02  49.00 
99.50 
No.  6  from  a  retail  druggist  of  this  city,  was  of  a  light  salmon 
color.  Before  the  blowpipe  it  gave  a  yellow  incrustation,  and 
the  moistened  mass  blackened  silver. 
Portion  insoluble  in  HC1  chiefly  .  BaO  S03  95.00 
Sesquioxide  of  Iron,  .  .  .  Fe203  2.25 
Oxide  of  Lead,  ....  PbO  1.00 
Carbonate  of  Lime,       .       .       .,     CaO  C02  1.50 
99.75 
Conclusion. — This  investigation  I  consider  sufficiently  exten- 
sive to  show  that  much  of  the  Lapis  calaminaris  of  our  shops  is  a 
worthless  and  inactive  article,  not  only  from  the  absence  of  car- 
bonate of  zinc,  to  which  it  owes,  or  ought  to  owe,  its  value  as  a 
remedial  agent,  but  also  from  the  presence  of  so  large  a  per 
centage  of  sulphate  of  baryta,  a  totally  insoluble  and  inert  salt. 
In  the  last  revision  of  our  Pharmacopoeia,  the  revisors,  in  sub- 
stituting the  present  Ceratum  Zinci  Carbonatis  for  the  old 
Turner's  Cerate,  (now  Ceratum  Calamine)  might  very  properly 
have  gone  a  step  farther  and  wholly  expunged  the  latter  pre- 
paration, for  it  must  be  apparent  that  it  has  little  or  no  other 
effect  than  simple  cerate,  and  is  consequently  a  superfluous 
article  in  our  officinal  standard. 
Philadelpliia,  Feb.  20th  1857. 
GLEANINGS— CHEMICAL,  PHARMACEUTICAL  AND  MEDICAL. 
Preparation  of  Ferris  Pulvis. — Hr.  Zangerle  suggests  that 
this  article  can  be  made  by  igniting  5  parts  of  protoxide  of  iron, 
6  parts  of  anhydrous  ferrocyanide  of  potassium,  and  1}  parts  of 
anhydrous  carbonate  of  potassa ;  the  ignition  is  maintained  until 
the  evolution  of  gas  ceases.  The  fused  mass,  on  cooling,  is 
thoroughly  washed  with  pure  water,  and  the  residue  dried.  The 
product  is  a  dark  gray  powder,  which  is  metallic  iron  in  a  state 
