A  NEW  ACID  BY  THE  OXIDATION  OF  NITRO  BENZINE.  329 
litmus.  It  penetrates  gutta  percha,  dissolves  out  the  dark  brown 
coloring  matter,  and  leaves  the  gutta  percha  undissolved,  and 
much  more  white.  It  also  acts  in  a  singular  and  somewhat 
similar  manner  upon  india  rubber.  The  India  rubber  while  in 
the  liquid  acid  exhibits  no  change,  but  immediately  on  being 
taken  out  its  wells  to  at  least  six  or  eight  times  its  original  dimen- 
sions, and  then  slowly  contracts  to  its  original  volume,  evidently 
from  expansion  and  liberation  of  absorbed  carbonic  acid,  and  it 
is  found  to  be  perfectly  white  throughout  its  substance.  These 
effects  upon  gutta  percha  and  india  rubber  may  prove  useful  for 
practical  purposes. 
The  liquid  acid  is  a  strong  insulator  of  electricity  ;  sparks 
(from  a  Ruhmkorff's  coilj  which  would  pass  readily  through  -^^ids 
of  an  inch  of  cold  air,  would  with  difficulty  pass  through  about 
J_th  of  an  inch  of  the  liquid  acid. 
70       ^  ... 
In  its  general  properties  it  is  somewhat  analogous  to  bisul- 
phide of  carbon,  but  it  possesses  much  less  solvent  power  over 
fatty  substances. — Chem.  Hews,  London,  May  11,  1861,  from 
Proceedings  of  the  Royal  Society. 
A  NEW  ACID  BY  THE  OXIDATION  OF  NITRO-BENZINE. 
When  nitro-benzine  is  oxidised  by  boiling,  either  with  a  solu- 
tion of  permanganate  of  potash  or  a  mixture  of  nitric  acid  and 
bichromate  of  potash,  there  is  found  among  the  products  a 
peculiar  acid.  The  oxidation  is  most  conveniently  effected  by 
the  last-mentioned  means,  but  care  must  be  taken  to  have  an 
excess  of  nitro-benzine.  The  new  acid  is  soluble  in  hot  nitro- 
benzine,  but  separates  on  cooling  in  small  white  crystals,  which 
remain  suspended  in  the  solvent.  This  is  separated  by  decanta- 
tion,  is  then  shaken  up  with  an  excess  of  ammonia,  which  dis- 
solves the  new  acid  and  another,  forming  a  deep  yellow  salt 
much  like  picric  acid  in  appearance.  The  solution  is  treated 
with  hydrochloric  acid,  which  causes  the  new  acid  to  deposit.  It 
is  then  washed  with  distilled  water  to  remove  chloride  of  am- 
monium and  also  some  yellow  acid  which  accompanies  it.  So 
purified,  it  has  the  following  properties  : — It  is  colorless,  has  a 
sharp,  slightly  bitter  taste,  and  presents  itself  in  slender  nee- 
dles irregularly  grouped  together.    It  fuses  at  a  temperature 
