%oH;  im™'}  Gleanings  from  the  European  Journals,  485 
These  differences  have  their  origin  in  differences  in  the  quality  of 
the  Nessler  reagent.  I  have  known  two  Nessler  reagents  which, 
although  in  the  course  of  hours  giving  the  same  depths  of  color  with 
the  same  quantity  of  ammonia,  required  very  different  times  for  the 
production  of  the  coloration.  One  sample  of  Nessler  reagent  gives 
its  maximum  of  color  almost  immediately,  and  another  sample  takes 
a  quarter  of  an  hour  or  an  hour  for  a  full  development. 
To  a  great  extent,  these  differences  depend  upon  whether  or  not 
a  sufficient  quantity  of  solution  of  corrosive  sublimate  has  been 'added 
to  the  finished  Nessler  reagents.  Whether  the  Nesslerising  takes  a 
couple  of  minutes,  or  whether  it  takes  an  hour,  is  a  matter  of  vital 
importance  to  those  persons  who  are  working  the  ammonia  process  of 
water  analysis;  and  since  the  employment  of  the  ammonia  process 
has  become  almost  universal,  I  have  deemed  it  to  be  worth  while  to 
direct  attention  to  the  necessity  of  a  careful  preparation  of  the  Ness- 
ler reagent.  —  Chem.  News  (Lond.\  J  ily  11,  1878. 
Falsifications  of  Albumen.— A.  Her  burger. — -Albumen  is  often 
adulterated  with  gum,  dextrin  and  starch,  To  detect  these  admix- 
tures, 30  grms.  of  the  sample  are  dissolved  ir  lukewarm  water.  After 
some  time  the  mass  is  stirred.  If  the  lie  aid  contains  many  white 
clots,  the  quality  is  inferior ;  that  is,  a  notable  quantity  of  the  albu- 
men has  been  coagulated  by  the  employment  of  too  high  a  tempera- 
ture during  desiccation.  The  solution  is  mixed  with  acetic  acid,  and 
then  some  alcohol  is  added  to  the  decanted  acid  liquid.  If  gum  is 
present,  a  precipitate  is  formed.  If  starch  has  been  added,  it  may 
be  recognized  in  the  usual  manner  by  means  of  iodine.  If  the  albu- 
men contains  sugar,  it  is  easily  recognized  by  the  use  of  Fehling's 
test. — -Ibid. 
Med  Ink. — Prof.  R.  Boettger  recommends  a  red  ink  which  is  not 
affected  by  powerful  chemical  agents.  The  ink  is  prepared  as  fol- 
lows :  Carmine  is  triturated,  in  a  porcelain  mortar,  with  a  little  solu- 
tion of  soluble  glass  ;  afterwards  more  of  this  solution  is  added,  until 
the  desired  shade  and  fluidity  has  been  attained.  The  ink  when  used 
dries  rapidly,  with  a  gloss,  and  when  not  in  use  should  be  protected 
from  contact  with  the  atmosphere  by  closing  the  vial  with  an  oiled 
cork.— Chem.  Centralbl,  1873,  No.  30. 
A  Remarkable  Reaction  of  Nitrobenzol. — Prof.  Merz  and  Dr.  Co- 
ray  observed  that,  on  heating  nitrobenzol  with  hydrate  of  potassium, 
