^"jS^iss?'^'"  }     Practical  Notes  from  Various  Sources.  375 
^excess  allowed  to  evaporate  by  exposure.  The  liquid  is  now  agitated 
with  ether  which  is  absolutely  free  from  alcohol,  and  the  etherial 
solution  well  shaken  with  a  small  quantity  of  water  containing  a  little 
acetic  acid ;  the  acetic  solution  is  treated  with  animal  charcoal,  con- 
centrated by  evaporation  and  again  treated  with  ammonia  and  ether 
on  the  spontaneous  evaporation  of  the  etherial  solution  the  atropine  is 
left  in  nearly  white  very  fine  crystals,  which  are  obtained  white  by 
recrystallizing  once  or  twice. — Chem.  Centralhl.,  1882,  p.  180. 
The  reddening  of  Carbolic  Acid  is  not  always  caused  by  light,  but 
may  take  place  in  the  dark,  and  rosolic  acid  is  not  always  found  in  the 
reddened  acid.  Ammonium  nitrite  produces  with  carbolic  acid  a  red 
color  which  gradually  changes  to  yellow,  brownish  green,  olive-green, 
finally  to  a  dingy  bluish  gray. — Phar.  Zeitung,  April  12,  1882. 
The  detection  of  mineral  acids  in  Vinegar  is  readily  effected,  accord- 
ing to  Chiappe,  by  a  0*1  per  cent,  solution  of  methylaniline- violet,  the 
€olor  of  which  is  not  altered  by  organic  acids,  while  even  largely  diluted 
mineral  acids  change  the  color  to  ultramarine-blue. —  Chem.  Zeitung, 
March  23,  1882,  p.  244;  Giorn.  Farm.  Chim.,  xxxi,  p.  76. 
.  ArtificiaUy-Golored  Claret  is  not  unfrequently  met  with.  According 
to  C.  Thomas,  Bordeaux  red,  a  new  coal-tar  product,  has  been  used 
for  coloring,  and  its  presence  may  be  detected  by  immersing  for  six 
or  eight  minutes  raw  unsized  silk  in  the  warmed  wine,  the  natural 
coloring  matter  of  which  will  dye  the  silk  of  a  violet-pink  color, 
changing  to  green  by  ammonia,  or,  if  old  wines  are  tested,  to  greenish, 
while  Bordeaux  red  will  impart  an  intense  red  color,  changing  to 
brown  by  ammonia.  Burnt  alum  assumes  with  the  natural  claret  a 
grayish  violet,  but  in  the  presence  of  Bordeaux  red  a  red  color. — Pep. 
de  Phar.,  1882,  p.  64. 
Another  method  depends  upon  the  recognition  as  sulphate  of  the 
sulphur  contained  in  the  Bordeaux  red  :  100  cc.  of  claret  is  mixed 
with  an  excess  of  baryta,  the  filtrate  freed  from  barium  by  ammonium 
carbonate,  evaporated  and  ignited  ;  the  ash  is  treated  with  dilute  hydro- 
chloric acid  and  the  filtrate  tested  with  barium  chloride.  0*5  gram 
Bordeaux  red  in  1  liter  of  claret  produced  a  distinct  precipitate. — Pe/p. 
de  Phar.,  1882,  p.  64,  111. 
