AmFe°b.y*iS7.arm'}        Gleanings  in  Materia  Medica.  73 
results.  This  is  re-dissolved  in  water,  precipitated  by  alcohol,  macer- 
ated in  alcohol,  washed  with  ether  and  dried  as  before.  It  still 
retains  about  10  per  cent,  of  ash,  mainly  calcium  phosphate,  which, 
by  dialysis,  is  reduced  one-half.  Its  elementary  composition,  after 
deducting  the  inorganic  constituents,  was  C  46.66,  H  7.35,  N  10.41, 
S  1.12.  Diastase  does  not  reduce  Fehling's  solution.  Its  solution, 
on  being  evaporated,  acquires  a  brown  color,  and,  on  boiling,  separates 
floccules,  which  are  soluble  in  caustic  soda.  With  Millon's  test  liquid 
it  gives  the  albumin  reaction,  and  with  Schdnbein's  reagent  a  tran- 
sient, intensely  blue  color.  This  last  test  is  best  applied  by  dissolving 
a  little  guaiac  resin  in  absolute  alcohol  and  adding  a  few  drops  of 
commercial  solution  of  hydrogen  peroxide,  followed  by  a  drop  of  very 
dilute  solution  of  diastase. 
Bronzing  of  Metals. — Very  handsome  colors  may  be  imparted  to 
metals,  according  to  Metallarbeiter ',  by  the  use  of  cold  solutions  of  the 
sulphides  of  arsenic  or  antimony.  The  articles  are  thoroughly 
cleaned  and  dried ;  a  thin  layer  of  a  dilute  solution  of  polysulphide 
of  ammonium  is  applied  with  a  soft  brush,  allowed  to  dry,  and  after 
brushing  off  the  separated  sulphur,  a  dilute  ammoniacal  solution  of 
sulphide  of  arsenic  is  applied.  The  color  thus  produced  resembles  that 
of  mosaic  gold,  and  becomes  deeper  and  ultimately  dark  brown  by 
repeating  the  application  of  the  arsenic  solution.  A  solution  of  sul- 
phide of  antimony  produces  a  rose-colored  tint,  which  may  be  deep- 
ened to  dark  red. 
By  polishing,  the  coating  acquires  a  bright  metallic  lustre,  and  by 
the  use  of  mordants  the  color  is  altered.  Brass  or  bronze  left  for  a 
long  time  in  contact  with  the  mordant  becomes  superficially  greenish- 
gray,  and  quite  glossy  on  being  polished  with  cloth  ;  if  now  treated 
with  the  above  solutions  a  dull  yellow  color  is  produced. 
The  bronzing  layer  may  be  re-dissolved  by  ammonia  or  sulphide  of 
ammonium,  and  the  sulphides  of  antimony  and  arsenic  may  be  dis- 
solved in  hydrate  or  sulphide  of  potassium  or  sodium. 
GLEANINGS  IN  MATERIA  MEDICA. 
BY  THE  EDITOR. 
Soluble  starch  has  been  observed  by  Dr.  J.  Dufour  (Jour.  Roy. 
Jlicr.  Soc,  Oct.  1886,  p.  819)  in  Saponaria  officinalis,  Lin.,  in  the  epi- 
dermal cells  of  the  leaves,  stem  and  floral  organs,  with  the  exception 
