132  Gleanings  from  Foreign  Journals.  {Am'li*l'S%£m~ 
Insoluble  Cement  for  Glass  is  obtained,  according  to  Prof.  H.  Schwarz,  by  dissolv- 
ing one  part  of  bichromate  of  potassium  for  every  5  parts  of  gelatin,  or  glue,  in  a 
solution  containing  from  5  to  10  percent,  of  the  latter.  After  having  been  applied  to- 
the  glass,  the  cement,  on  exposure  to  the  sunlight,  loses  its  property  of  swelling  and 
dissolving  in  water,  in  consequence  of  the  partial  reduction  of  chromic  acid. — 
Ibid.,  No.  45. 
Estimation  of  Vanillin  in  Vanilla. — F.  Tiemann  and  W.  Haarmann  exhaust  finely 
cut  vanilla  with  ether,  the  solution  is  somewhat  concentrated  by  evaporation,  and 
then  repeatedly  agitated  with  two  portions  of  a  mixture  consisting  of  equal  volumes 
of  water  and  concentrated  solution  of  sodium  bisulphite.  The  mixed  aqueous- 
solutions,  containing  the  vanillin,  are  treated  with  some  sulphuric  acid,  the  liberated 
sulphorous  acid  is  expelled  by  a  moderate  heat,  and  the  vanillin  extracted  by  agita- 
tion with  ether.  On  the  evaporation  of  the  ether,  and  drying  over  sulphuric  acid?, 
pure  vanillin  is  left  behind. 
The  authors  obtained,  by  this  method,  from  Mexican  vanilla  1*69,  from  Bourbon 
vanilla  1*91  and  2-48,  and  from  Java  vanilla  2*75  per  cent,  of  vanillin,  which,  in 
the  two  last  named  varieties,  is  associated  with  an  oil  of  a  disagreeable  odor,, 
whereby  its  flavor  is  modified. — Ibid.,  No.  47,  from  Ber.  Chem.  Ges. 
Soluble  Blood  Powder  is  obtained,  according  to  G.  LeBon,  by  evaporating  the  blood 
under  decreased  pressure  and  at  a  temperature  not  exceeding  that  of  the  body.  The 
author  submitted  a  sample,  18  months  old,  to  the  Paris  Academy.  By  agitation 
with  water  it  was,  in  a  few  minutes,  converted  into  a  fine  red  solution,  possessing 
all  the  properties  of  defibrinated  blood,  showing  the  same  behavior  in  the  spectro- 
scope and  coagulating  on  boiling.  It  is  soluble  in  an  acidulated  solution  of  pepsin,, 
and  is  recommended  as  very  nourishing. —  Chem.  Centralbl.,  1875,  No,  51,  from 
Compt.  rend..,  lxxxi. 
A  good  Copying  Ink  jrom  Extract  of  Logwood  is  obtained  by  treating  250  grams  of 
coarsely  powdered  American  extract  of  logwood  in  a  suitable  bottle,  with 
3  kilos  distilled  water.  When  this  is  completely  saturated  with  the  soluble  coloring 
matters,  say  in  about  one  or  two  weeks,  the  clear  solution  is  carefully  decanted 
from  the  sediment,  about  20  grams  of  acetate  of  manganese,  dissolved  in  a  little 
water,  are  added  to  the  liquid,  the  whole  is  well  mixed,  and  solution  of  acetate  of 
iron  carefully  dropped  in,  until  a  deep  violet-blue  color  is  obtained.  It  is  advisable 
to  set  the  mixture  aside  for  a  few  days  to  ascertain  the  change  of  color  produced. 
The  ink  must  be  protected  from  the  influence  of  the  sunlight,  and  instead  of  gum 
arabic,  solution  of  dextrin  or  sugar  is  preferably  added  to  it. — Ibid.,  No.  52,  from 
Ind.  BL,  xii 
Solubility  of  Oils  in  Glacial  Acetic  Acid. — Mr.  Barnes'  experiments  on  this 
subject  (see  page  29  of  January  number),  were  made  with  an  acid  solid  at  480  F. 
Mr.  W.  H.  Symons,  using  acetic  acid,  remaining  solid  up  to  6o°  F.,  found  that  one 
volume  of  it  will  dissolve  in  4  vols,  of  almond,  olive,  cod  liver  and  'linseed  oil,  and 
mix  in  all  proportions  with  the  oils  of  turpentine  and  lemon.  He  also  gives  the 
following  formulas  for 
Linimentum  Terebinthina  Aceticum :  oil  of  turpentine,  4  fluidounces  $  glacial 
acetic  acid,  solid  at  6o°  F.,  1  fluidounce,  and  camphor  liniment,  4  fluidounces. 
