47  6  Gleanings  from  the  French  Journals.  }  ^^ig?™'' 
minutes  with  50  or  60  grams  of  caustic  soda  dissolved  in  a  little  water, 
whereby  dense  yellow  anhydrous  oxide  of  bismuth  is  formed.  This 
is  well  washed  by  decantation  and  afterwards  mixed  with  continued 
agitation  with  sufficient  nitric  acid  added  in  small  quantities,  equal  to 
48*5  grams  of  nitric  anhydrid  ;  should  the  mixture  become  too  hard,  & 
little  water  is  added,  sufficient  to  impart  a  pasty  consistence,  and  again 
heated  in  the  water-bath  for  a  few  minutes,  when  it  becomes  perfectly 
white  and  rather  more  liquid.  It  is  then  diluted  with  little  water, 
collected  upon  a  filter  resting  upon  a  linen  support,  washed  with  about 
twice  its  volume  of  water,  expressed  and  dried.  The  yield  is  about 
265  grams.— V  Union  phar.,  August,  p.  229-231. 
Alf.  Riche  has  investigated  the  causes  of  the  variable  composition 
of  subnitrate  of  bismuth,  and  experimented  with  bismuth,  to  which  1 
and  2  per  cent,  of  lead  were  added.  By  following  the  process  of  the 
French  Codex,  in  evaporating  the  nitric  acid  solution  to  two-thirds  and 
adding  to  40  or  50  times  its  volume  of  water,  the  following  results- 
were  obtained  : 
Distilled  water :  The  precipitate  contained  15-10  per  cent.  N2Os. 
Common  water  of  Paris :  13*78  to  12*42  N2Os  and  traces  of  lead. 
Common  water  with  ammonia,  leaving  an  acid  reaction  :  9*80  to  ll*8o 
N2Os  and  about  J  per  cent,  of  lead. 
Common  water  with  ammonia  in  slight  excess  :  0*6o  to  2*09  N2Os 
and  8  to  10  per  cent,  of  lead.  Carbonate  of  sodium  used  in  place  of 
ammonia  gave  similar  results. 
Well-water  containing  lime,  chiefly  sulphate:  7*79  to  11  '68  N205 
and  775  per  cent,  precipitate  with  sulphuric  acid,  of  which  '056  was 
lead,  the  remainder  sulphate  of  calcium. 
The  precipitates  with  ammonia  and  sodium  carbonate  were  obtained 
from  the  acid  mother  liquors,  decanted  from  the  precipitates  with 
water. 
The  author  regards  the  subnitrate  with  the  maximum  proportion  of 
nitric  acid  as  above  as  the  most  useful  for  medicinal  purposes,  and  is 
opposed  to  increasing  its  quantity  by  the  partial  neutralization  of  the 
mother  liquor ;  the  bismuth  remaining  in  the  mother  liquor  may  be 
recovered  by  precipitation  with  an  alkali  and  utilized  in  various  ways. 
Should  the  bismuth  contain  silver  and  lead,  the  former  is  removed  by 
adding  to  the  acid  solution  before  concentration  a  few  drops  of  hydro- 
chloric acid,  the  latter  in  a  similar  way  by  a  little  sulphuric  acid,  at  the 
