^°^'d^.?iS*'^™'}      Gleanings  from  the  German  Journals.  611 
magnesium  and  barium  acetates.  The  determinations  of  glycerin 
gave  as  a  mean  9*59  per  cent.  Melting-point  determinations,  made  in 
an  open  tube,  gave  for  specimens  of  various  sources  figures  varying 
from  29*4  to  33*4°  C,  while  those  made  in  a  closed  tube  gave, 
with  one  exception,  a  uniform  melting  point  at  34*3°. — Arch,  der 
Fharm.,  1888,  830. 
Detection  of  Colophonium. — A  solution  of  this  in  glacial  acetic  acid, 
on  addition  of  a  drop  of  concentrated  sulphuric  acid,  assumes  an  in- 
tense red  to  blue- violet  color,  soon  changing  to  yellowish -brown,  hav- 
ing decided  fluorescence.  In  the  examination  of  soaps,  the  separated 
fatty  acids  are  dissolved  in  glacial  acetic  acid  by  application  of  heat, 
allowed  to  cool,  and  then  the  sulphuric  acid  (sp.,  gr.  1*53)  added. 
Serviceable  for  the  detection  of  rosin  in  bees'- wax. — Th.  Morawski, 
Chem.  Rpt,  1888,  270. 
Nitrous  acid  in  water,  in  quantities  not  detected  by  diphenylamine, 
is  indicated  on  addition  of  hydriodic  acid  by  the  liberation  of  iodine 
after  standing  a  short  time. —  W.  Kalmann,  Chem.  Rpt.,  1888,  269. 
Eseridine  an  alkaloid  of  the  Calabar  bean  and  closely  related  to  phy- 
sostigmine  is  convertible  into  the  latter  by  warming  with  dilute  acids, 
consequently  its  solutions  in  dilute  acid  should  always  be  made  in  the 
cold.  Its  action  on  the  system  is  to  cause  certain  diarrhoea  with  little 
or  no  action  on  the  central  organs;  its  toxic  dose  is  six  times  greater 
than  that  of  physostigmine.  Used  in  1  ^  solution  made  by  adding 
one  drop  dilute  sulphuric  acid  for  every  O'l  gm.  eseridine,  which  solu- 
tion keeps  unchanged  for  long  periods. — Rdsch.,  1888,  841. 
Ferrous  solutions. — The  reduction  of  oxidized  and  discolored  ferrous 
solutions  can  be  accomplished  by  freezing  the  solutions.  Languepin 
observed  that  a  30%  ferrous  sulphate  solution  which  had  become 
strongly  colored  and  deposited  a  red-brown  precipitate,  after  freezing 
and  subsequent  liquefaction,  reassumed  its  original  green  color,  the 
precipitate  also  partially  disappearing.  The  solution  had  also  lost 
considerably  its  tendency  to  oxidize. — {Arch,  de  Fharm.)  Rdsch.j 
1888,  844. 
Solution  of  Bromides. — Dr.  Erlenmayer  recommends:  Potassium 
and  sodium  bromide  of  each  4  gm.,  ammonium  bromide  2  gm.,  water 
of  ammonia  1  drop,  carbonated  mineral  water  600  gm. — Fharm.  Ztg.y 
1888,  644. 
Hydrargyrum  phenylicum  or  carbolicum  used  as  a  syphylitic  specific 
is  prepared  as  follows :  Potassium  phenol  is  first  made  by  taking  94 
