556 
A  NEW  ANTISEPTIC. 
decided  impression  that  the  "crushed"  capsules  were  inferior  in 
quality  to  the  '^poppy-heads." — Trans,  of  Brit.  Conf,  inPharm. 
Journ.^  Lond.,  Oct.  1,  1870. 
A  NEW  ANTISEPTIC. 
The  hydrated  chloride  of  aluminium,  to  which  Mr.  John  Gam- 
gee  has  recently  drawn  the  attention  of  medical  men  and  of  the 
general  public,  appears  to  be  a  valuable  antiseptic.  It  is  quite 
as  potent  as  chloride  of  zinc  or  carbolic  acid,  and  is  at  the  same 
time  non-poisonous,  and  devoid  of  unpleasant  smell  of  every 
kind.  These  qualities  will  no  doubt  insure  its  being  extensively 
used,  and  at  no  distant  date  we  may  expect  it  to  displace  the 
antiseptics  which  are  at  present  in  vogue. 
It  is  somewhat  strange  that  this  substance  should  have  been 
BO  long  overlooked  as  a  possible  antiseptic,  and  Mr.  Gamgee 
certainly  deserves  credit  for  suggesting  the  utilisation  of  it  for 
this  purpose.  The  reason  why  it  has  been  passed  over  is  probably 
to  be  sought  in  its  not  being  a  waste  product  in  any  common 
chemical  manufacture.  The  anhydrous  chloride  of  aluminium, 
which  is  manufactured  in  order  to  serve  for  the  preparation  of 
metallic  aluminium,  is  far  too  costly  on  account  of  the  trouble- 
some nature  of  the  process  by  which  it  is  prepared — to  wit,  by 
passing  chlorine  at  high  temperatures  over  a  mixture  of  alumi- 
na and  charcoal.  By  placing  the  anhydrous  chloride  of  alumi- 
nium in  water,  it  is  of  course  converted  into  hydrated  chloride. 
The  most  economical  process  for  the  preparation  of  the  hy- 
drated chloride  of  aluminium  appears  to  be  by  double  decompo- 
sition between  sulphate  of  alumina  and  chloride  of  calcium  (both 
of  which  are  cheap  commercial  products).  When  solutions  of 
these  two  salts  are  mixed  together,  sulphate  of  lime  is  formed 
and  appears  as  a  precipitate,  whilst  the  hydrated  chloride  of 
aluminium  remains  dissolved. 
On  allowing  the  aqueous  solution  to  evaporate  at  a  very  gentle 
heat  and  afterwards  cooling,  crystals  of  hydrated  chloride  are 
produced.  If  an  attempt  be  made  to  drive  off  the  water  from 
the  hydrated  chloride  by  the  application  of  heat,  decomposition 
will  take  place.    Hydrochloric  acid  is  evolved  under  these  con- 
