516  Inorganic  Chemistry  of  the  U.S. P.  {^Zh£%?: 
standard  ones  and  are  easily  carried  out.  Its  chemical  composition 
is  variable  but  is  approximately  BiOC7H5Os.  It  is  also  official  in 
the  Swiss  and  in  the  British  Pharmacopoeias. 
Kaolinum,  Kaolin. — "A  native  aluminum  silicate  consisting  chiefly 
of  the  pure  silicate  (H2Al2Si209  -f  H20)  powdered  and  freed  from 
gritty  particles  by  elutriation."  It  is  official  in  the  British  Pharma. 
copceia  under  the  same  name,  while  Bolus  alba  is  official  in  the 
German  Pharmacopoeia.  Kaolin  is  a  very  pure  clay.  It  was  intro- 
duced into  the  Pharmacopoeia  because  it  enters  into  the  preparation 
of  cataplasma  kaolini,  but  its  use  outside  of  this  is  very  extensive, 
being  used  as  a  dusting  powder,  and  combined  with  antiseptics  as 
an  application  to  wounds ;  it  is  also  employed  as  an  excipient  in 
making  pills  of  silver  salts  and  of  potassium  permanganate.  It  does 
not  decompose  these  substances  as  most  of  the  organic  excipients  do. 
Cataplasma  Kaolini,  Cataplasm  of  Kaolin. — This  is  similar  to  cer- 
tain proprietary  clay  preparations.  It  is  undoubtedly  a  very  useful 
preparation  and  not  an  entirely  novel  one,  for  the  peasants  of  Central 
Europe  have  long  employed  a  mixture  of  clay  and  glycerin  as  a 
household  remedy  for  many  ailments,  especially  where  poultices 
were  indicated. 
The  U.S. P.  preparation  consists  of  kaolin,  577  grammes;  boric 
acid,  45  grammes;  glycerin,  375  grammes,  together  with  thymol 
methyl  salicylate  and  oil  of  peppermint. 
Liquor  Sodii  Phosphatis  Compositus,  Compound  Solution  of  Sodium 
Phosphate. — This  compound  is  prepared  by  triturating  sodium  phos- 
phate and  sodium  nitrate  in  a  mortar  with  citric  acid  until  complete 
liquefaction  has  taken  place,  then  adding  sufficient  water  to  make  a 
product  of  which  I  c.c.  contains  I  gramme  of  sodium  phosphate. 
This  solution  should  be  kept  well  stoppered  and  in  a  moderately 
warm  place.  The  tests  for  identity  are  the  standard  tests  for  phos- 
phate, nitrate  and  citric  acid.  A  preparation  similar  to  this  has 
been  in  commerce  for  some  time. 
Magnesii  Sulphas  bffervescens  (Effervescent  Magnesium  Sul- 
phate).— This  preparation  may  be  used  instead  of  the  magnesii  citras 
effervescens  of  the  1890  Pharmacopoeia,  which  has  been  dismissed. 
A  similar  compound  is  official  in  the  British  Pharmacopoeia.  This 
preparation  is  more  stable  than  the  effervescent  citrate  of  magnesia. 
Mangani  Hypophosphis  (Manganese  Hypophosphite,  Mn(PH202)2 
+  H20). — "  It  should  contain  not  less  than  97  per  cent,  of  pure 
