AmjSy!^o5.amj'}     Study  of  Fruit  and  Vegetable  Colors.  303 
The  raspberry  color  was  obtained  from  the  wine,  and  was  verified 
by  using  the  preserved  fruit. 
The  strawberry  color  was  obtained  from  the  fresh  fruit,  and  was 
verified  from  the  preserved  fruit. 
The  beet  juice  was  prepared  from  the  fresh  vegetable. 
Such  dyestuffs  and  drugs  as  are  commonly  used  as  sources  of 
color,  and  which  were  deemed  worthy  of  consideration  in  this  con- 
nection, were  obtained  in  the  unground  or  whole  condition,  through 
the  kindness  of  Mr.  F.  P.  Sher,  of  Smith,  Kline  &  French  Company, 
and  were  prepared  for  use  by  the  author  himself. 
In  considering  the  best  and  most  effective  method  oi  making  a 
comparison  of  so  many  different  colors  it  was  deemed  advisable  to 
reduce  all  of  the  solutions  to  a  uniform  color  density,  rather  than  to 
base  the  comparisons  upon  the  solutions  made  up  to  a  certain  uni- 
form weight  in  volume  strength,  owing  to  the  very  great  differences 
existing  in  the  tinctorial  power  of  the  various  fruits  and  dyestuffs 
when  prepared  in  the  lorm  of  aqueous  infusions  or  decoctions,  as  was 
done  in  the  present  work. 
The  solutions  were  prepared  as  follows  :  In  the  cases  of  fruits 
where  jellies  or  canned  fruits  or  fruit  preserves  were  used,  the  pulpy 
material  was  separated  by  straining  and  the  liquid  reduced  to  a 
given  color  density  by  dilution  with  water  and  comparison  with  an 
arbitrary  standard  which  had  previously  been  prepared  for  this 
purpose. 
Such  drugs  as  logwood,  safffower,  saffron,  etc.,  were  prepared  by 
making  a  decoction  and  digesting  it  at  1 00°  C.  until  the  coloring 
matter  of  the  drug  appeared  to  have  been  thoroughly  extracted, 
then  filtering  and  diluting  to  the  standard  color  density  as  before. 
A  few  examples  of  coal  tar  or  synthetic  colors  (four  in  all),  taken 
from  samples  of  materials  found  to  be  in  actual  use  by  manufac- 
turers in  simulating  fruit  colors,  are  also  included  for  better  com- 
parison. 
The  liquids  having  been  thus  prepared  the  first  comparison  was 
made  by  observing  the  color  of  5  c.c.  of  the  original  liquid,  con- 
tained in  a  5  inch,  §  inch  test  tube,  provided  with  a  foot,  and  then 
noting  the  change  which  was  produced  by  the  addition  of  0  5  c.c. 
of  31-9  per  cent,  hydrochloric  acid  to  one  sample,  and  0-5  c.c.  of  10 
per  cent,  ammonium  hydroxide  solution  to  another  sample  of  the 
same  quantity  each  contained  in  a  similar  test  tube. 
