140  Aqueous  Mixtures  of  Chlorate  of  Potash.        \Amkt™h  issT™' 
passes  into  solution  and  is  deposited  in  the  crystalline  condition  as  soon 
as  the  temperature  falls.  This  accounts  for  the  change  so  far  as  a 
portion  of  the  chlorate  is  concerned,  but  does  not  explain  how  the 
whole  becomes  ultimately  so  altered.  This,  I  think,  is  brought  about 
in  the  following  manner.  When  the  temperature  rises  a  portion  of 
the  chlorate  dissolves  and  when  the  temperature  falls  it  is  deposited  as 
crystals.  On  the  temperature  again  rising  a  fresh  portion  of  the 
powdered  chlorate  is  dissolved,  because  the  powder  dissolves  more 
readily  than  the  crystals,  and  this  second  portion  is  in  turn  deposited, 
either  as  a  fresh  crop  of  crystals,  or,  more  probably,  as  an  addition  to 
those  already  formed.  In  this  way,  with  each  day's  variations  in 
temperature,  the  process  goes  on  until,  as  already  stated,  the  whole  of 
the  chlorate  takes  the  form  of  pretty  large  tabular  crystals. 
The  theory  that  this  change  is  at  least  very  'much  accelerated  by  the 
variable  temperature  of  an  ordinary  bedroom  or  sitting-room  was  con- 
firmed in  the  following  manner.  A  mixture  containing  one  drachm 
of  finely  powdered  chlorate  in  one  ounce  of  water  was  kept  for  a  month 
in  a  place  where  the  temperature  did  not  vary  more  than  two  or  three 
degrees.  At  the  end  of  that  time  it  was  found  that  the  chlorate  had 
passed  into  a  state  of  small,  somewhat  granular  crystals,  showing  only 
a  slight  tendency  to  form  crystalline  plates.  In  this  condition,  I 
believe,  it  would  be  less  objectionable  for  use  as  a  gargle  than  in  the 
other  case  where  a  number  of  sharp-edged  plates  were  formed  ;  but, 
nevertheless,  it  appears  that,  even  under  the  most  favorable  conditions, 
it  is  impossible  to  retain  chlorate  of  potash  in  a  state  of  fine  powder  in 
presence  of  water. 
From  what  has  been  stated  it  will  be  apparent  that  none  of  the  sub- 
stances employed  had  the  effect  of  preventing  crystallization,  and  that 
a  single  day's  exposure  to  the  variable  temperature  of  a  sitting-room 
was  sufficient  to  produce  such  an  alteration  of  the  chlorate  as  to  render 
the  gargle,  etc.,  unfit  for  use.  Treacle,  tragacanth  and  honey  seemed 
to  have  a  slight  influence  in  retarding  the  process  of  crystallization ; 
the  crystals  formed  in  these  mixtures  being  of  somewhat  smaller  size. 
They  failed,  however,  to  accomplish  the  object  in  view,  which  was  not 
simply  retardation  but  prevention.  Thus,  then,  we  have  shown  that 
the  practice  of  prescribing  such  mixtures  is  open  to  a  serious  objection  ; 
but  there  is  still  another  clause  to  the  indictment. 
Such  gargles  or  mixtures  are  frequently  directed  to  be  taken  in 
regular  specified  quantities;  the  intention  being  that  each  quantity 
