Am.  Jour.  Pharm.  1 
Dec.  1875.  / 
Varieties. 
567 
picric  acid  from  the  grass -tree  resin  of  Australia,  obtained  in  abundance  from  the  stems 
of  one  or  two  species  of  Xantorrhcea^  is  considerable,  as  we  stated  in  an  article  in  our 
fourth  volume,  p.  1225  and  G.  C.Wittstein  has  recently  drawn  attention  to  the  neglect 
of  this  prolific  source  of  supply.  It  is  known  in  pharmacy  under  the  name  of  "gum 
acroides,'  and  in  the  Australian  colonies  as  "grass-tree  gum,"  and  "black  boy  gum." 
The  advantages  of  using  this  substance  for  the  manufacture  of  picric  acid  are  two-fold. 
First,  the  material  is  cheap  5  second,  the  yi^ld  is  large.  About  one  hundred  and 
fifty  grains  of  the  pulverized  resin  were  placed  In  a  beaker  glass,  and  750  grains 
crude  nitric  acid,  of  specific  gravity  i'i6,  poured  over  it  j  the  beaker  glass  was  cov- 
ered with  a  glass  capsule  and  digested  at  a  gentle  heat.  The  mass  soon  swelled  up, 
and  a  deep  brown  crust  formed  over  the  liquid.  This  crust  needed  to  be  broken  up 
from  time  to  time  with  a  glass  rod.  After  about  three  hours,  nitrous  fumes  ceased 
to  be  evolved,  and  the  mass  was  allowed  to  cool.  The  next  day,  he  found  the  bot- 
tom of  the  beaker  covered  with  a  thick  layer  of  yellow  crystals.  Above  this,  was 
a  brownish-red  tarry  mass,  which  hung  together  in  a  lump.  This  was  taken  out  and 
again  digested  with  375  grains  nitric  acid  \  but  there  was  almost  no  action,  at  least 
no  nitrious  acid  was  formed,  and  no  crystals  were  deposited  from  this  second  liquid  on 
cooling,  showing  that  it  Is  unnecessary  to  treat  the  resinous  mass  with  nitric  acid  a 
second  time.  In  the  present  case,  it  was  desirable  to  lose  as  little  as  possible  of  the 
product  sought  5  hence,  after  the  crystals  that  formed  had  been  taken  out,  the  second 
liquid  was  added  to  the  mother  liquor  and  evaporated  to  dryness.  The  first  crystals 
were  added  and  the  adhering  nitric  acid  driven  off  at  212^  Fah.  The  total  residue 
weighed  100  grains,  almost  two-thirds  of  the  resin  taken  ;  It  was  yellow  and  crystal- 
line, and  contained  nothing  amorphous  but  single  crystals  of  oxalic  acid.  The  picric 
acid  thus  obtained,  after  recrystalllzing  to  secure  the  oxalic  acid,  weighed  seventy-five 
grains.  Hence,  the  yield  Is  fifty  per  cent,  of  the  crude  material. — Jour,  of  App.  Sci. 
[Lond.],  Oct.  I,  1875. 
Influence  of  Tannin  on  Vegetation. — By  M.  Mercadante. — When  an  aque- 
ous extract  of  the  dung  of  cows  and  goats  Is  treated  with  tannin,  nearly  the  whole 
of  the  bases  and  acids  are  rendered  Insoluble.  Again,  if  the  aqueous  extract  of 
dung  is  treated  with  hydrochloric  acid,  and  the  resulting  precipitate,  after  washing, 
is  dissolved  in  ammonia,  and  the  ammonlacal  solution  saturated  with  calcium  phos- 
phate, tannin  will  precipitate  from  such  a  solution  all  the  fertilizing  Ingredients  ex- 
cept the  phosphoric  acid.  Alkaline  tannates  act  In  the  same  way.  The  above  Is 
offered  as  an  explanation  of  the  sterility  of  soil  containing  tannin,  especially  as  re- 
gards the  legumlnosae  and  gramlnaceas. — Journ.  Chem.  Soc,  September,  1875,  from 
Gazzetta  Chimica  Italiana,  Iv,  484-486. 
The  Two  Sugars  Obtained  from  Sugar  o7  Milk. — By  H.  Fuda'cowski, — 
The  author  found,  in  1866,  that  by  the  action  of  dilute  acids  0.1  s  igar  of  milk,  two 
glucoses  are  formed,  which  both  show  right-handed  polarisation.  He  is  now 
continuing  this  research. — Ibid.^  from  Deut.  Chem.  Ges.  Ber.,  viil,  599. 
IsoPROPYL  and  Allyl  Sulphocyan ates. — By  G.  Gerlich. — During  the  pre- 
paration of  a  large  quantity  of  mustard  oil  from  potassium  sulphocyanate  and  the 
