Am.  Jour.  Pharm  ) 
Sept.,  1877.  ; 
Varieties. 
473 
in  all  parts  of  the  plant,  is  distinguished  by  its  strong  fluorescence  and  stability,  as 
shown  by  the  following  experiment:  Two  unripe  berries  were  crushed  with  a  little 
water,  the  mass  dried  on  a  water  bath,  the  residue  exhausted  with  alcohol,  the  solu- 
tion again  evaporated,  and  the  remainder  dissolved  in  water.  The  filtered  solution 
was  shaken  at  a  gentle  heat  with  animal  charcoal,  which  takes  up  the  compound. 
On  then  digesting  it  with  alcohol  and  a  little  ammonia,  a  liquid  is  obtained  showing 
a  beautiful  blue  fluorescence,  even  if  very  dilute.  The  solution  may  be  evaporated 
repeatedly  without  the  compound  losing  in  fluorescence,  which  reappears  on  the 
addition  of  ammonia. — R.  Fassbender.  Jour.  Chem.  Soc,  Feb.,  from  Deut.  Chem. 
Ges.  Ber. 
Eosin. — A.  Baeyer  has  given  certain  additional  particulars  as  to  the  manufacture 
of  eosin.  Fluorescein  is  obtained  by  heating  5  parts  of  anhydrous  phthalic  acid  to 
2000  along  with  7  parts  of  resorcin.  The  mass  swells  up  and  solidifies  in  the  course 
of  three  to  six  hours.  Fluorescein  is  extracted  from  this  crude  product  by  boiling 
with  alcohol.  It  is  a  feeble  acid,  and  dyes  silk  and  wool  a  fast  yellow  with  a  red- 
dish cast.  For  the  preparation  of  eosin  the  fluorescein  is  suspended  in  4  parts  of 
glacial  acetic  acid  and  solution  of  bromine  in  glacial  acetic  acid,  containing  20  per 
cent,  of  the  former,  is  added.  Tetrabrom-fluore^cein  (eosin)  separates  out  in  red 
crystals. —  Chem  Nenvs,  July  13,  1877. 
Origin  of  Petroleum. — Mr.  H.  Byasson  has  been  led  by  the  following  experi- 
ment to  give  a  scientific  explanation  of  the  formation  of  petroleum  :  If  a  mixture 
of  vapor  of  water,  carbonic  acid  and  sulphuretted  hydrogen  be  made  to  act  upon 
iron  heated  to  a  white  heat  in  an  iron  tube,  a  certain  quantity  of  liquid  carburets 
will  be  formed.  This  mixture  of  carburets  is  comparable  to  petroleum.  The  for- 
mation of  petroleum  can  thus  be  naturally  explained  by  the  action  of  chemical  for- 
ces. The  water  of  the  sea,  penetrating  into  the  cavity  of  the  terrestrial  crust, 
carries  with  it  numerous  materials,  and  especially  marine  limestone.  If  the  subter- 
ranean cavity  permits  these  new  products  to  penetrate  to  a  depth  where  the  tempe- 
rature is  sufficiently  high,  in  contact  with  metallic  substances,  such  as  iron  or  its 
sulphurets,  we  have  a  formation  of  carburets.  These  bodies  will  form  part  of  the 
gases  whose  expansive  force  causes  earthquakes,  volcanic  eruptions,  etc.  Petroleum 
\?  always  found  in  the  neighborhood  of  volcanic  regions  or  along  mountain  chains. 
In  general  it  will  be  modified  in  its  properties  by  causes  acting  after  its  formation, 
such  as  partial  distillation,  etc.  Petroleum  deposits  will  always  be  accompanied  by 
salt  water  or  rock-salt.  Often,  and  especially  where  the  deposit  is  among  hard  and 
compact  rocks,  it  will  be  accompanied  by  gas,  such  as  hydrogen,  sulphuretted 
hydrogen,  carbonic  acid,  etc. — Jour.  App.  Sci.,  March,  from  Revue  Ind. 
Fermentation  of  Glycerin. — Redtenbacher  found  that  when  a  mixture  of  glycerin, 
water  and  yeast  ferments,  it  yields  acetic  and  propionic  acids,  and  Berthelot  obtained 
alcohol  by  fermenting  a  solution  of  glycerin  with  chalk  and  casein. 
