Am.  Jour  Pharm.  ( 
August,  1882.  j 
Chemical  Notes.- 
S97 
amount  of  oxide  of  copper  from  time  to  time^  and  hy  a  simple  method 
of  titration,  also  devised  by  Mr.  Weil,  the  exact  amount  of  copper 
oxide  to  be  added  can  be  readily  and  quickly  determined. 
These  processes  can  be  also  applied  to  the  deposition  of  all  metals, 
such  as  nickel,  cobalt,  antimony,  tin,  etc.,  upon  castings  of  iron  and 
other  metals. —  Comptes  Rendus,  93,  1018. 
Organic  Chemistry. — On  the  Crystallization  of  Anhydrous  Grape- 
sugar. — Dr.  Arno  Behr  describes  the  method  of  obtaining  well-crystal- 
lized anhydrous  glucose  from  aqueous  solutions.  Hitherto  glucose  had 
been  obtained  anhydrous  only  from  alcoholic  solutions,  either  solutions 
of  ordinary  alcohol,  or,  according  to  Soxhlet's  recently-patented  method, 
from  methylic  alcohol.  From  aqueous  solutions  had  been  obtained 
only  the  hydrate  in  small  and  laminated  crystals,  which  were  very  hard 
to  free  from  the  mother  liquor.  Behr  found  that  upon  ])utting  a  crys- 
tal of  anhydride  in  an  aqueous  solution,  instead  of  its  taking  up  water 
of  hydiation,  there  separated  out  over  night  a  mass  of  hard,  sharply- 
crystallized  anhydrous  glucose,  which  was  readily  purified  from  syrup 
in  a  centrifugal.  The  solution  from  which  this  crystallization  took 
place  contained  18  per  cent,  water,  and  of  100  parts  dried  material  87*5 
were  pure  glucose.  Behr  found,  moreover,  that  it  was  not  even  neces- 
sary to  start  the  crystallization  by  a  fragment  of  solid  glucose,  but  that 
for  concentrated  solutions  and  moderately  elevated  temperatures,  the 
crystallization  of  anhydride  is  the  rule  and  not  the  exception.  The 
l^ure  product  gotten  this  way  resembles  cane-sugar  in  many  ways,  and 
can  be  used  for  many  of  the  applications  of  the  latter.  Its  sweetness 
is  to  that  of  cane-sugar  in  about  the  ratio  of  1  to  If.— Chem. 
Ges.,  XV,  p.  1104. 
Artificial  Piperine. — Riigheimer  describes  the  successful  attempt  to 
build  up  the  alkaloid  piperine  by  the  same  methods  as  those  adopted 
by  Ladenburg  in  the  pre])aration  of  artificial  atropine.  The  action  of 
phosphorus  pentachloride  upon  piperic  acid  yielded  the  acid  chloride, 
which  was  then  made  to  act  upon  piperidine.  The  result  of  the  reac- 
tion, freed  from  side  products,  was  pi])ei"inc,  which  after  purification 
by  recrystallization  from  benzol  and  ligroin  fused  at  127  to  128°C.,  and 
gave  figures  on  analysis  closely  according  with  those  demanded  by  the 
formula.  Natural  ])iperine,  according  to  IliigheimcT's  observation, 
fuses  at  128  to  129.5°C.  In  some  text-books  the  fusing  point  of 
piperine  is  erroneously  given  on  Pelletier's  authority  at  100  to  11()°C. 
