AmNo°vU,r^79arm- }  Chemical  Notes.  553 
by  Messrs.  Johnson  and  Matthey,  gave  me  a  magnificent  series  of 
colored  phenomena.  The  hydrogen  lines  first  appeared,  then  the  D 
line — not  the  sodium  line,  be  it  understood,  for  the  green  line  was 
absent — and  lastly  the  green  line  of  magnesium  (£),  and  then,  as  the 
temperature  was  increased,  mixtures  of  all  these  lines,  with  the  blue 
line  (the  D  line)  being  always  the  most  brilliant.  In  this  experiment 
only  two  volumes  of  hydrogen  were  collected.  From  gallium  and 
arsenic  no  gas  of  any  kind  was  obtained.  From  sulphur,  and  some  of 
its  compounds,  sulphurous  anhydrid  was  always  obtained.  From 
indium  hydrogen  was  given  off  in  vacuo  before  heating,  while  from 
lithium  no  less  than  100  volumes  of  hydrogen  were  given  off.  The 
conditions  of  the  experiments  were  always  the  same,  the  only  variable 
being  the  substance  itself. —  Chemical  News,  Sept.  5th,  1879. 
Organic  Chemistry. —  On  the  Carbohydrates  of  the  Helianthus  tube- 
rosus  (^Jerusalem  Artichoke). — Dieck  and  Tollens  have  made  an  examina- 
tion of  these  tubers  with  a  view  of  determining  what  species  of  carbo- 
hydrates were  present.  They  sum  up  their  results  as  follows:  1st. 
In  the  tubers  examined  by  them  little  or  no  inulin  was  found,  but 
laeoulin  in  considerable  amount,  and  right-rotating  sugar.  2d.  Laeou- 
lin  has  the  composition  C6H10O5  which  is  ascribed  to  starch,  dextrin 
and  the  gums.  It  is  optically  inactive,  and  agrees  in  other  respects  with 
gum  and  with  dextrin.  It  gives  the  alcoholic  fermentation  with  yeast. 
3d.  Laeoulin  yields  laeoulinic  acid  on  boiling  with  sulphuric  acid.  4th. 
The  sugar  produced  from  laeoulin  reduces  Fehling's  solution  strongly, 
and  possesses  a  specific  rotatory  power  to  the  left  of  \a\  \d  at  20°C, 
which  equals  520  reckoned  for  laeoulin,  and  470  reckoned  for  sugar. 
5th.  The  juice  expressed  from  the  artichoke,  when  fermented  with 
yeast,  yields,  in  abundant  amount,  a  spirit  which  after  a  time  has  a  very 
pure  taste.  Farther  study  seems  quite  desirable  here.  Previous  heat- 
ing with  sulphuric  acid  increases  somewhat  the  yield.  6th.  In  the  fer- 
mented juice  mannite  and  glycerin  and,  in  one  case,  succinic  acid  were 
recognized. — Ann.  der  Ch.  und  Ph.,  198,  p.  228. 
Partial  Synthesis  of  Milk-sugar. — E.  Demole  has  found  that  the  two 
glucoses  produced  by  the  action  of  acids  upon  milk-sugar  may  be  made 
to  lose  a  molecule  of  water  and  reunite  to  form  a  molecule  of  lactose 
again.  He  recognizes  a  profound  difference  between  milk-sugar  and 
cane-sugar  in  this  respect.  Two  molecules  of  dextro-glucose  reunited, 
and  with  loss  of  water,  will  not  in  any  case  reconstitute  cane  sugar. 
