VARIETIES. 
271 
by  potash  salts.  However,  this  is  not  the  case,  as  when  to  a  solution  of 
potash  soap,  which  has  been  obtained  by  boiling  fats  with  a  solution  of 
caustic  potash,  a  considerable  quantity  of  chloride  of  potassium  has  been 
added,  the  separation  of  the  soap  does  nob  follow ;  the  salt  dissolves  in  the 
soap,  and  the  solution  remains  clear. 
From  this  result  it  is  evident  that  it  is  impossible,  as  in  the  ordinary  pro- 
cess of  making  soda  soap,  to  separate  potash  soap  as  such,  by  the  aid  of  salts. 
The  only  way,  therefore,  to  prepare  potash  soap  from  fats  and  caustic  pot- 
ash is  to  evaporate  its  solution  to  dryness,  by  which  a  sort  of  extract-like 
substance  is  obtained,  containing  glycerine  and  other  impurities. 
When  a  pure  potash  soap  is  required,  it  can  only  be  made  by  the  direct 
union  of  the  oily  acids  with  caustic  potash,  and  not  by  the  saponification  of 
oils.* — Annals  of  Pharmacy,  &ept. 1852. 
Notice  of  the11  Ice  Spring"  in  the  Rocky  Mountains,  (from  a  letter  of  Geo. 
Gibbs,  Esq.) — The  Ice  Spring,  so  called,  is  considered  by  the  mountaineers 
as  one  of  the  curiosities  of  the  great  trail  from  the  States  to  Oregon  and  Cali- 
fornia. It  is  situated  in  a  low  marshy  "  swale"  to  the  right  of  Sweet  water 
river,  and  about  forty  miles  from  the  South  Pass.  The  ground  is  filled  with 
springs,  and  about  eighteen  inches  beneath  the  turf  lies  a  smooth  and  hori- 
zontal sheet  of  ice,  which  remains  the  year  round,  protected  by  the  soil  and 
grass  above  it.  At  the  time  of  our  passing,  July  12th,  1849,  it  was  from 
two  to  four  inches  thick,  but  our  guide  told  us  that  he  had  seen  it  a  foot 
deep.  It  is  perfectly  clear,  and  beautifully  disposed  in  hexagonal  prisms, 
separating  readily  at  the  natural  joints.  The  ice  has  a  slightly  saline  taste, 
the  ground  about  it,  as  with  the  Sweetwater  and  Platte  river  country  gen- 
erally, being  impregnated  with  salts,  and  the  water  at  one  spot  near  by 
tasted  of  sulphur.  Not  the  least  singular  circumstance  was  the  smoothness 
of  the  upper  surface  of  the  stratum,  although  formed  beneath  soil. — SUHmari1* 
Journal. 
SaccJiarated  Medicinal  Powders. — Some  of  the  most  useful  of  our  phar- 
maceutical preparations  are  thoseknown  as  tinctures,  which  hold  in  solution 
many  of  the  most  active  principles  of  vegetable  substances.  Yet  as  alcohol, 
either  pure  or  more  or  less  diluted  with  water,  constitutes  the  greater  part 
of  their  composition,  the  frequent  administration  of  this  substance  is, 
♦Dr.  Wittstein  is  in  error  here,  as  a  pure  potash  soap  can  be  separated  from 
its  solutions  and  from  glycerine,  when  made  in  the  ordinary  way,  by  a  concen- 
trated solution  of  caustic  potash,  in  which  it  is  insoluble.  The  best  method  to 
make  the  potash  or  soft  soap  of  the  London  Pharmacopoeia  is  to  boil  olive  oil  with 
a  sufficient  quantity  of  a  solution  of  caustic  potash  until  it  is  saponified  ;  then  to 
concentrate  the  solution  by  heat  in  a  water-bath,  and  afterwards  to  add  a  strong 
solution  of  caustic  potash  to  it,  when  the  potash  soap  will  float  on  the  surface,  if 
the  solution  be  sufficiently  strong,  and  may  be  removed.  By  placing  the  soap  in 
a  funnel,  the  excess  of  caustic  alkali  and  glycerine  will  drain  from  it.  By  this 
method  an  excellent  soap,  of  a  clear,  gelatinous  appearance,  is  obtained. — Editors 
fothe  "  Annals." 
