Am.  Jour,  Pharm.  ") 
Aug.  1, 1871.  J 
Bromide  of  Cerium. 
343 
bility  of  keeping  vaccine  one  year  !  !  under  mercury,  as  per  essay  of 
David  Stewart  in  a  recent  number;  the  good  crust  referred  to  having 
been  submerged  in  June,  1870,  and  those  returned  by  Dr.  T.  being 
its  progeny  in  June,  1871.  2d.  It  may  suggest  the  idea  that  a  much 
longer  preservation  is  practicable ;  and,  3d.  The  postage  stamp  indi- 
cates a  rare  degree  of  honesty,  also  a  more  important  principle  (if 
possible)  in  such  publications  when  made  m  scientific  periodicals. 
David  Stewart,  Ph.  D. 
Port  Penn,  Delaware,  24:t7i  June,  1871. 
St.  George's,  June  21st,  1871. 
Dear  Sir, — I  enclose  you  three  fresh  vaccine  crusts.    The  one  you  sent  me 
was  good,  for  which  I  am  much  obliged  to  you,  and  regret  I  did  not  think  when 
I  asked  you  to  send  it  to  me  to  leave  a  stamp  to  pay  the  postage. 
Yery  respectfully  yours, 
Wm.  a.  Tatem. 
D.  Stewart,  M.  D. 
BROMIDE  OF  CERIUM. 
By  Charles  Bullock. 
Having  a  request  from  a  medical  friend  to  furnish  him  with  several 
ounces  of  bromide  of  cerium,  the  preparation  of  the  salt  was  started 
from  the  oxalate,  it  being  the  only  available  commercial  salt  of 
cerium. 
The  oxalate  was  calcined  in  a  porcelain  capsule,  over  a  gas  furnace, 
with  occasional  stirring  of  the  contents  of  the  capsule,  until  the  oxa- 
late was  converted  into  the  yellowish  brown  sesquioxide  of  cerium, 
losing  one-half  its  weight  by  the  change. 
The  sesquioxide  was  dissolved  in  hydrochloric  acid  (with  copious 
evolution  of  chlorine),  and  to  the  chloride  carbonate  of  soda  was 
added,  which  precipitated  the  cerium  as  a  white  carbonate,  insoluble 
in  an  excess  of  the  alkaline  carbonate. 
The  carbonate  of  cerium  was  dissolved  in  hydrobromic  acid,  requir- 
ing nearly  twice  the  weight  of  sesquioxide  in  bromine  as  hydrobromic 
acid  for  saturation. 
The  solution  of  bromide  of  cerium  decomposes  while  evaporating, 
even  at  a  low  temperature,  disengaging  acid  fumes.  When  evaporated 
to  dryness,  and  pulverized,  the  salt  has  a  light  chocolate  color,  the 
taste  is  somewhat  sweet  and  very  styptic.  It  is  very  deliquescent, 
and  dissolves  to  a  considerable  extent  in  alcohol  of  95  per  cent.  The 
