154 
Benzoate  of  Calcium. 
j  Am.  Jour.  Pharm. 
I      April,  1881. 
An  alcoholic  extract  of  the  bark  was  treated  with  benzin  to  remove 
fatj  then  redissolved  in  stronger  alcohol,  and  this  solntion  poured  into 
water  acidulated  with  acetic  acid,  when  a  greenish-brown  resinous  pre- 
cipitate was  obtained,  which,  on  being  dried  at  a  gentle  heat,  gave  off 
vapors  having  a  decided  acid  reaction  on  litmus.  This  resin  is  colored 
dark  purple  by  alkalies  and  dissolves  completely  in  potassa  solution. 
(For  researches  on  the  constituents  of  butternut  bark  consult  essays  by 
Chas.  O.  Thiebaud  and  E.  S.  Dawson  in  Amer.  Jour.  Pharm.,"  1872^ 
p.  253,  and  1874,  p.  167.) 
BENZOATE  OF  CALCIUM. 
By  .James  T.  Bhinn. 
Becid  at  the  Phamaceutical  Meeting^  March  15. 
Having  been  requested  by  Dr.  Albert  H.  Smith  to  prepare  some 
benzoate  of  calcium  for  a  patient  we  at  first  made  it  extemporaneously 
by  rubbing  together  the  benzoic  acid  and  carbonate  of  calcium  with  a 
little  water  until  effervescence  ceased,  making  a  pill  mass  of  the  ben- 
zoate thus  formed  and  dispensing  it  in  gelatin  capsules.    As  time  was 
not  always  allowed  for  thorough  combination,  the  formation  of  carbonic 
acid  gas  in  the  capsules  sometimes  caused  them  to  swell  and  become 
distorted,  and  it  Avas  thought  best  to  have  the  salt  all  ready  prepared. 
The  ^proportions  of  benzoic  acid  and  calcium  in  the  benzoate  are  113 
to  20,  or  of  the  crystallized  acid  and  carbonate  of  calcium,  122  to  50. 
Hence  the  following  formula  for  its  manufacture : 
Take  of  benzoic  acid,  .  •    3iv  gr.  xxxii  (1952  grains). 
Calcium  carbonate,         .  ,5i      ^i  (800  grains). 
Boiling  water,  .  .    Oiv  or  q.s. 
Mix  the  acid  and  precipitated  chalk  thoroughly  in  a  large  mortar  and 
add  water  gradually  to  allow  most  of  the  carbonic  acid  gas  to  escape 
and  prevent  frothing  over  of  the  liquid.  When  the  combination  has 
taken  place,  or  nearly  so,  the  mass  is  transferred  to  a  porcelain  dish 
and  dissolved  in  the  remainder  of  the  boiling  water,  with  the  exception 
of  a  slight  excess  of  carbonate  of  calcium.  Filter,  while  hot,  into  a 
shallow  dish,  when  crystals  will  form  on  cooling;  The  mother-liquors 
may  be  evaporated  twice  more  and  yield  more  crystals,  the  whole  pro- 
duct being  about  ^iv  3v. 
The  salt  is  in  feathery  crystals,  of  a  silky  lustre,  odorless,  with  but 
slight,  rather  alkaline,  taste,  and  is  soluble  in  about  24  parts  of  water. 
