234 
Calomel  in  Japan. 
Am.  Jour.  Phario. 
May,  1894. 
crystals  of  calcium  sulphate.  He  refers  to  Porter  Smith's  Contribu- 
tions towards  the  Materia  Medic  a  and  Natural  History  of  China  for 
an  account  of  the  manufacture.  Smith,  however,  takes  his  infor- 
mation solely  from  Pearson's  account  on  p.  59,  Vol.  III.  of  Sir  J. 
Davis's  work  On  the  Chinese.  I  have  not  seen  this  book  but  it  is 
clear  from  Porter  Smith  that  Pearson  again  has  only  derived  his 
information  from  the  Chinese  Materia  Medica,  Pun-tsaou-kang-muh, 
and  not  from  his  own  observation,  and  it  amounts  to  this : — Com- 
mon salt  and  mercury,  of  each  I  oz.;  alum,  2  ozs.,  or  salt,  mercury, 
copperas,  and  saltpetre,  in  some  such  proportions  are  rubbed  together 
and  put  into  an  iron  bowl,  which  is  then  covered  with  a  roomy 
earthen  dish  well  luted  down.  This  is  exposed  to  the  heat  of  a 
strong  charcoal  fire  for  four  or  five  hours,  when  water  is  thrown  on 
the  cover  and  the  cover  taken  off.  On  its  inner  surface  the  calomel 
is  found  adhering  in  the  form  of  a  beautiful,  feathery,  white  subli- 
mate. Ten  parts  of  mercury  are  said  to  yield  about  eight  parts  of 
calomel.  Dr.  Geerts's  paper,  already  referred  to,  contains  essen- 
tially the  same  account,  translated  from  the  Japanese  version  of  the 
Chinese  work. 
Lastly,  there  is  a  paper,  in  the  Japanese  language,  on  the  manu- 
facture of  keifun  at  Ise,  which  is  the  forerunner  of  the  present  one. 
That  paper  appeared  in  1887,  in  the  Journal  of  the  Tokyo  Chemical 
Society,  written  by  Mr.  T.  Shimidzu,  M.E.,  F.C.S.,  my  former  pupil 
and  colleague,  and  it  was  his  description  to  me  of  what  he  had  seen 
that  led  to  my  own  visit  to  Ise  in  company  with  Professor  Haga  in- 
the  following  year.  In  one  or  two  points  I  have  availed  myself  of  this 
paper  to  make  my  own  account  more  complete. 
Of  the  Specific  Properties  of  Keifun. — Keifun  is  in  very  thin, 
minute  scales,  lustrous,  transparent  and  white  or  faintly  cream- 
colored.  It  might  be  described  as  micaceous  calomel.  1  o  the  touch 
it  is  soft  and  smooth.  Measured  in  bulk,  dry,  it  is  four  times  as 
voluminous,  more  or  less,  as  the  ground  calomel  prepared  by  the 
European  process,  and  can  be  readily  scattered  by  a  puff  of  the 
breath.  Rubbed  hard  in  a  porcelain  mortar,  it  gives  the  brown 
resinous  streak  characteristic  of  calomel,  and  the  evidence,  therefore, 
according  to  pharmaceutical  authorities,  of  its  freedom  from  corrosive 
sublimate.  Exposed  to  bright  sunlight,  it  gradually  assumes  a  light 
brown  color;  a  color,  that  is,  having  no  affinity  to  gray  or  black. 
Moisture  does  not  seem  to  favor  this  change,  which  is  certainly  not 
