406 
PREPARATION  OF  FANCY  LEATHERS,  ETC. 
ounces  of  the  substance  treated,  and  consider  that  as  the  fin- 
ished preparation  ?  He  assumes  the  position  that  this  quan- 
tity, if  the  percolation  is  conducted  right,  will  on  the  average 
contain  at  least  three-fourths  of  the  virtues  of  the  substance 
treated,  and  the  great  loss  in  alcohol  occasioned  by  pushing  the 
percolation  to  get  the  last  fourth,  as  well  as  the  injury  to  the 
drug  by  the  heat  of  evaporation,  will  more  than  counterba- 
lance the  loss  of  what  extractive  matter  remains  in  the  perco- 
lator. 
To  establish  the  truth  of  this  assumption  would  require  a 
series  of  analyses,  as  well  as  a  corresponding  series  of  thera- 
peutical experiments,  and  whilst  admitting  the  great  proba- 
bility that  the  results  in  the  main  would  be  satisfactory  if  con- 
ducted by  a  careful  manipulator,  they  could  hardly  be  de- 
pended upon  in  general  hands.  The  strongest  reasons  in  its 
favor  are  the  entire  absence  of  heat  in  preparation,  and  the 
simplicity  of  the  process ;  being  in  fact  only  the  first  steps  of 
the  process  for  a  common  tincture.  If  there  were  any  checks 
known  by  which  the  uniformity  of  the  results  could  be  insured, 
the  idea  of  Dr.  Squibb  might  be  adopted,  but  until  then  it  is 
doubtful  whether  the  average  results  would  equal  those  now 
attained  by  the  old  recipes. 
ON    THE    PREPARATION  OF  FANCY    LEATHERS— KID, 
CHAMOIS,  &c. 
By  F.  Crace  Calvert  F.  R.  S. 
Extracted  from  the  3d  Cantor  Lecture. 
Fancy  Leathers  Allow  me  now  to  give  you  a  slight  insight 
into  the  methods  of  preparing  various  fancy  leathers,  such  as 
Morocco,  Russia  enamelled,  tawed,  or  kid  leather,  used  for  sol- 
diers' belts,  gloves,  &c,  a?id  lastly  all  leathers  used  for  wash- 
leather,  gloves,  &c.  Until  the  middle  of  the  eighteenth 
century  Morocco  leather  was  wholly  imported  from  that  country, 
for  it  was  in  1735  that  the  first  Morocco  works  were  established 
in  Paris,  and  similar  manufactories  were  soon  set  up  in  various 
parts  of  the  Continent  and  in  this  country.  The  process  by 
which  Morocco  leather  is  prepared  is  as  follows  : — The  goat 
