100  Bromide  of  Calcium.  {AM^7hCm^ 
forming  a  distinct  layer,  consisting  of  one  volume  of  castor  oil  and 
two-thirds  of  a  volume  of  abietene,  so  that  by  this  means  sophistica- 
tions of  castor  oil  with  other  fixed  oils  may  be  easily  detected  and 
quantitatively  determined. 
BROMIDE  OF  CALCIUM. 
By  James  E.  Mercein. 
The  good  effects  experienced  by  Prof.  W.  A.  Hammond  and  other 
well-known  physicians,  in  the  substitution  of  bromide  of  calcium  for 
bromide  of  potassium  as  a  sedative  and  hypnotic,  have  brought  this 
salt  into  somewhat  prominent  notice  during  the  past  year.  The  fact 
that  its  wholesale  price  seemed  to  be  exorbitant  in  proportion  to  the 
cost  of  the  ingredients,  first  induced  me  to  try  and  make  it  for  my- 
self. A  thorough  search  in  nearly  a  dozen  works  on  chemistry  gave 
me  no  clue  whatever,  only  one  or  two  authors  giving  the  name  even. 
In  Miller's  Chemistry,  however,  and  in  Watt's  Dictionary  of  Chem- 
istry, there  is  a  general  description,  but  nothing  to  serve  as  a  working 
formula.  But  after  various  trials  I  have  succeeded  in  making  the 
salt  to  my  satisfaction,  and  herewith  give  the  modus  operandi  for  the 
benefit  of  others. 
Five  ounces  of  bromine  and  two  and  a  half  pints  of  water  were  put 
together  in  a  half  gallon  specie  jar.  A  stream  of  sulphuretted  hydro- 
gen was  then  passed  slowly  into  this,  care  being  taken  to  place  the 
end  of  the  delivery  tube  so  as  to  touch  the  surface  of  the  bromine. 
This  was  continued  until  the  bromine  was  all  taken  up,  and  the  re- 
sulting liquid  was  of  a  muddy  yellow  color  with  a  copious  deposit  of 
sulphur.  It  was  then  filtered,  transferred  to  a  capsule  and  gently 
warmed,  to  drive  off  any  trace  of  S205,  and  again  filtered.  The  re- 
sult was  a  strong  solution  of  hydrobromic  acid,  specific  gravity  13°. 
In  order  to  free  this  from  any  possible  impurity,  it  was  distilled  by  a 
sand-bath  heat  until  four-fifths  had  passed  over.  It  was  then  satu- 
rated with  precipitated  carbonate  of  lime,  which  was  added  in  slight 
excess,  so  that  even  after  applying  a  gentle  heat,  a  slight  quantity 
remained  undissolved.  This  solution  of  bromide  of  calcium  was  fil- 
tered, evaporated  by  a  water-bath  to  a  syrupy  consistence,  then  re-' 
moved  from  the  fire  and  stirred  until  it  cooled.  The  result  was  six 
ounces  of  bromide  of  calcium  in  fine,  granular  powder,  possessing 
every  characteristic  of  the  salt,  and  freely  soluble  in  twice  its  weight 
