Am.  lour.  FharUi  ) 
Oct.,  i88o.  / 
Chemical  Notes. 
493 
as  to  forbid  their  substitution  for  each  other.  If  the  resin  be  rubbed 
with  distilled  water,  and  the  mixture  be  then  poured  upon  a  filter- 
paper,  the  filtrate  will  be  colorless,  almost  tasteless,  and  free  from  bit- 
terness. Under  the  same  conditions  the  filtrate  from  the  dried  extract 
is  dark  colored  and  very  bitter. 
Resin  of  leptandra  will  never  run  together  at  ordinary  temperatures 
nor  in  any  atmosphere.  On  the  contrary,  extract  of  leptandra  upon 
exposure  to  a  moist  atmosphere,  or  if  not  well  dried,  will  run  into  a 
hard  lump.  The  yield  of  dry  extract,  made  by  the  process  I  suggest^ 
will  average  lo  per  cent,  of  the  weight  of  the  root  employed. 
CHEMICAL  NOTES. 
By  Prof.  Samuel  P.  Sadtler,  Ph.D. 
Inorganic  Chemistry. —  On  the  Atomic  Weight  and  General  Charac- 
ters of  the  New  Elements  Ytterbium  and  Scandium. — Nilson,  the  dis- 
coverer of  the  latter  of  these  two  claimants  for  recognition  as  elements, 
has  worked  up  some  9J  kilograms  of  the  rare  mineral  euxenite,  and 
has  extracted  therefrom  the  mixed  oxides  of  the  rare  earths.  He  con- 
siders that  there  are  seven  of  these  earths,  viz. :  Scandia,  vtterbia,, 
thulia,  erbia,  terbia,  a  new  earth  provisionally  designated  by  Soret  as  X 
(holmia),  and  yttria.  Prof.  Cleve,  the  discoverer  of  thulium  and,  inde- 
pendently with  Soret,  of  holmium,  extracted  these  mixed  earths  at  the 
same  time  from  15  kilos  of  gadolinite,  so  that  the  two  investigators 
had  6  to  7  kilos  of  the  rare  earths  to  divide  between  them,  which 
was  done  by  Prof  Nilson  undertaking  the  study  of  ytterbium,  scan- 
dium and  holmium,  while  Prof.  Cleve  retained  the  earths  erbia  and 
thulia.  After  a  long  and  tedious  purification  of  the  ytterbia  he  was 
enabled  to  get  it  perfectly  free  from  other  earths  and  determined  the 
atomic  weight  of  the  element.  The  mean  of  seven  determinations 
was  I73'0i.  Ytterbia,  YbgOg,  is  a  white,  very  heavy  and  infusible 
powder,  which  is  slowly  attacked  by  acids  in  the  cold  or  at  a  gentle 
heat ;  at  a  boiling  temperature,  however,  is  readily  dissolved  by  dilute 
acids.  Its  solutions  are  colorless  and  show  no  absorption  spectrum. 
Its  sp.  gr.  is  9'i75.  Its  solutions  have  a  very  sweet  and  yet  astringent 
taste.  It  gives  no  flame  coloration,  but  the  sparic  spectrum  of  its 
chloride  contains  a  large  number  of  characteristic  lines. 
Four  determinations  of  the  atomic  weight  of  scandium  were  made, 
the  mean  of  which  was  44  03.     Scandia,  Sc^Og,  is  a  white,  loose 
