102 
IMPURITIES  AND  ADULTERATIONS. 
per  cent,  alcohol  only  a  portion  of  it  dissolved  while  an  oily 
liquid  gradually  separated  at  the  bottom  of  the  test  tube.  This 
sediment  was  again  treated  with  200  times  its  volume  of  strong 
alcohol,  with  which  it  yielded  a  turbid  mixture,  gradually  sep- 
arating an  oily  layer,  which  produced  upon  paper  a  stain  easily 
recognized  as  greasy  and  quite  distinct  from  resinous.  A  por- 
tion of  the  so-called  copaiva  was  slowly  evaporated  at  a  mod- 
erate heat ;  the  odor  developed  at  first  was  more  like  copaiva, 
but  subsequently  quite  distinct  and  terebinthinate:  the  residue 
was  perfectly  transparent,  liquid,  had  a  bland,  afterwards  acrid 
taste,  and  formed  with  caustic  potassa  and  ammonia  a  milky 
mixture.  From  these  experiments,  I  pronounced  the  copavia 
adulterated  with  a  fixed  oil  and  probably  some  terebinthinate 
oleoresin. 
Castile  Soap.  A  sample  of  mottled  Castile  Soap  had  a  some- 
what suspicious  appearance  ;  the  color  of  the  body  of  soap  was  the 
of  a  dirtier  brown  than  usual,  the  intermixed  oxide  of  iron  had 
a  dull  reddish  brown  color  only  on  the  outside  of  the  bar,  while 
the  interior  retained  its  black  color  for  four  weeks.  200  grains 
of  it  in  its  commercial  state  without  previous  desiccation,  were 
incinerated;  the  ashes  weighed  90  grains,  which  shows  the 
enormous  amount  of  45  per  cent,  of  inorganic  constituents  aside 
from  the  water.  The  ashes  were  but  partly  soluble  in  water, 
and  the  solution  contained  soda,  a  little  potassa,  carbonic  and 
some  muriatic  acid ;  the  solution  was  evaporated  to  dryness  in 
the  presence  of  muriatic  acid  and  the  residue  taken  up  with 
acidulated  water,  when  a  trace  of  silica  remained  undissolved  ; 
it  was  entirely  free  from  lime  and  sulphuric  acid. 
The  undissolved  portion  was  partly  soluble  in  nitric  acid  and 
this  solution  afforded  abundant  evidence  of  the  presence  of  lime  ; 
no  sulphuric  acid  was  found,  but  on  supersaturating  with  am- 
monia, a  dense  white  precipitate  appeared  again.  I  did  not  go 
any  further  for  want  of  time  to  ascertain  whether  the  portion 
dissolved  by  nitric  acid  was  phosphate  of  lime  or  not. 
That  portion  of  the  ashes  which  had  not  been  taken  up  by  water 
and  cold  nitric  acid,  was  fused  with  pure  carbonate  of  potassa, 
which  combined  with  some  silica,  leaving  a  portion  of  lime  and 
oxide  of  iron  behind. 
200  grs.  of  the  soap  was  dissolved  in  boiling  85  per  cento 
