98  Abstracts  from  the  French  Journals.   {Am-^S'im"m ' 
to  products  of  decomposition.  (2)  Having  defecated  a  decoction  of 
the  plant  by  neutral  acetate  of  lead  and  filtering,  the  glucoside  may- 
be precipitated  by  sub-acetate  of  lead,  in  the  form  of  a  plumbic 
compound  ;  and  may  be  isolated  by  diffusing  the  precipitate  in  dis- 
tilled water,  or  preferably  in  alcohol,  passing  a  current  of  sul- 
phuretted hydrogen,  boiling,  filtering  and  concentrating  rapidly  in 
vacuo.  Another  method  is  to  digest  the  precipitate  with  water,  and 
add  diluted  sulphuric  acid  in  just  sufficient  quantity  to  precipitate 
the  lead;  then  proceed  as  before.  (3)  When  a  free  glucoside  exists 
in  a  plant  nearly  free  from  tannin,  the  plant  may  be  digested  with 
alcohol ;  filter,  evaporate  the  alcohol  and  crystallize.  This  is  the 
method  with  strophanthin  and  ouabain.  (4)  The  "lime  process," 
recommended  by  Tanret  consists  in  treating  the  pulverized  plant 
with  milk  of  lime  for  24  hours,  when  the  mass  is  put  into  a  displace- 
ment apparatus.  'I  he  glucoside  may  now  be  precipitated  by  a 
reagent,  coagulated  by  ebullition,  or  taken  up  by  an  appropriate 
solvent.  This  method  is  used  for  vincetoxin  and  condurangin.  (5) 
When  the  plant  contains  much  tannin,  or  when  the  production  of 
sulphuretted  hydrogen  is  to  be  avoided,  precipitate  the  decoction 
by  sub  acetate  of  lead,  mix  the  precipitate  with  slacked  lime  and 
dry  it  in  a  water-bath  ;  the  powder,  introduced  into  a  displacement 
apparatus,  is  treated  by  alcohol,  whose  evaporation  reveals  the  glu- 
coside. Pambotanin  has  been  made  in  this  way.  Concerning 
solvents,  I  may  say  that,  whilst  the  alkaloids  require  such  substances 
as  benzin,  ether,  chloroform,  etc.,  the  glucosides  dissolve  only 
[?  editor]  in  alcohol  and  water.  Some  of  the  latter  have  a  remark- 
able affinity  for  water.  Under  the  action  of  weak  mineral  acids  the 
glucosides  decompose  and  form  new  bodies.  The  object  oi  this 
paper  is  to  put  young  chemists  upon  their  guard  against  the  errors 
resulting  from  the  use  of  certain  reagents,  such  as  picric  acid,  iodide 
of  potassium  and  mercury,  and  tannin,  said  to  give  characteristic 
results  with  the  alkaloids,  as  they  likewise  precipitate  a  certain 
number  of  the  glucosides. — M.  Bocquillon-Limousin,  R'epert.  de 
Phar.,  Nov.  10,  1890. 
Characters  of  Glucosides. — Certain  glucosides,  such  as  amyg- 
dalin  and  solanine,  contain  nitrogen.  Many  others,  such  as  sesculin 
and  arbutin,  are  tertiary  combinations.  Some  of  them,  like 
caincin  have  a  distinctly  acid  reaction.  Others  are  basic,  and,  like 
the  alkaloids,  are  precipitated  by  potash;    Tanret's  vincetoxin 
