484  Laboratory  Notes.  {Am'Jc°"M^rm' 
notwithstanding  the  difficulty  of  gain  by  hygroscopic  water  while 
weighing.  The  last  four  weighings  were,  for  dish  and  contents,  26*895, 
26*894,  26*893,  26-895.  (See  reference  to  Mr.  Palmer  in  Note  II.) 
The  residue  of  quinia  from  ether  solution  is  amorphous  and  does  not 
yield  a  perfectly  crystallizable  sulphate.  Taking  this  residue  as  a  mono- 
hydrate,  nearly  21  parts  of  the  washed  ether  are  required  to  dissolve  a 
precipitate  of  quinia  containing  1  part  of  anhydrous  alkaloid. 
The  solubility  of  quinia  in  ether  is  given  by  van  der  Burg  at  23  parts 
(ether  of  sp.  gr.  072  and  i8°C),  by  Merck  at  60  parts,  Fliickiger  and 
Hanbury  21  parts,  by  Hesse — for  quinia  trihydrate — at  about  an  equal 
weight  of  ether,  by  J.  Regnault  at  22*6  parts  (i5°C.) 
V.  Valuation  of  Six  Samples  of  the  Citrate  of  Iron  and  Quinia 
in  the  Trade. 
The  samples  were  obtained  indiscriminately  from  different  dispensing 
drug  stores  in  Michigan.  Only  the  total  alkaloid  was  determined.  This 
was  done  by  extraction  with  chloroform,  as  follows  :  a  weighed  portion 
of  the  scales  was  dissolved  in  water  in  a  wide  tube  with  a  stopper,  a 
small  amount  of  tartaric  acid  was  added  (to  prevent  precipitation  of 
ferric  hydrate,  a  hindrance  to  the  separation  of  chloroform),  solution  of 
sodium  hydrate  was  added  to  alkaline  reaction,  and  the  liquid  repeatedly 
shaken  with  successive  portions  of  chloroform,  the  chloroform  being 
drawn  off  into  a  weighed  beaker  and  evaporated  until  a  portion  of  the 
chloroform  caused  less  than  one  milligram  increase  of  weight  to  the 
beaker.  The  total  residue  in  the  beaker  was  now  dissolved  in  water 
acidulated  with  sulphuric  acid,  the  solution  treated  with  a  slight  excess 
of  sodium  hydrate  solution,  then  extracted  with  successive  portions  of 
chloroform,  as  before,  and  the  residue  from  this  solution  was  dried  at 
2I2°F.  to  a  constant  weight.  This  residue  is  given  as  the  alkaloid, 
containing,  according  to  Allen,  4*28  per  cent,  water.  The  determina- 
tions were  done  by  W.  J.  Holloway,  in  June,  1876,  with  the  follow- 
ing results  :  The  samples  gave 
5#2         I2'2         8*7         9'0         11*4         8*3  per  cent  of  alkaloid. 
VI.  The  Presence  of  Sulphates  in  Citrate  of  Iron  and  Quinia. 
In  each  of  the  six  samples,  numbered  above,  Mr.  Holloway  found 
sulphates  present.  In  three  of  them  the  quantities  of  sulphuric  anhy- 
dride were  found  to  be  less  than  1  per  cent,  of  the  preparations  ;  in  the 
other  three  the  quantities  were  found  to  be  respectively  6-5,  3*5  and 
I 
