A  i>    lour.  Hnar-i. 
Dec. .  t88o 
Chemical  Notes. 
613 
<3.  Leading  constituents, 
Petroleum  spirit. 
Heptane,  C^H^^, 
its  homologues. 
S}).  gr.  of  sample  at  15-5^0.,  0*690 
Boilg  point  of  sample,  55°C. 
[  Very  slight  solvent 
Solvent  action  of  sample 
on  coal-tar  pitch, 
action.  Liquor 
only  amber-yel- 
low   after  pro- 
[     longed  contact. 
Behavior  of  sample  on  [ 
agitating  3  parts  of  it  !  No  apparent 
(cold)   witn  I  part  of  J      lution.  The 
Shale  naptha. 
Heptylene,  C^H^^, 
its  homologues. 
0-718 
56°C, 
Behaves  similar- 
ly to  petroleum 
spirit. 
;olu 
fused  crystals  of  abso- 
quids  are 
miscible. 
The  liquids  form 
a  homogeneous 
mixture. 
Coal-tar  naphtha 
and  benzol. 
Benzin,  C|.Hj., 
its  homologues. 
0-876 
8o°C. 
Readily  dis- 
solves pitch, 
forming  deep 
brown  solu- 
The  liquids 
form  a  ho- 
mogeneous 
mixture. 
lute  carbolic  acid  (Cal 
vert's),  l_  , 
 Chem.  News^  Oct.  15,  1880,  p.  189. 
Technical  Chemistry. — Recent  improvements  in  the  Manufacture  of 
Coal-tar  Colors. — Prof.  J.  W.  Mallet,  in  a  recent  review  of  the  develop- 
ment of  the  coloring  industry,  makes  the  following  statements:  In 
regard  to  the  original  so-called  anilin  colors,  one  of  the  most  important 
changes  has  been  the  application  on  the  great  scale  of  Coupler's  pro- 
cess, or  a  modification  of  it,  for  making  anaiin  red  (rosanilin  salts)  with- 
out the  use  of  arsenic.  This  process,  consisting  essentially  in  heating 
together,  in  the  presence  of  an  acid,  nitro-benzin  and  commercial  anilin 
oil  of  high  boiling  point,  rich  in  toluidin,  has  been  adopted  by  several  of 
the  largest  manufacturers.  The  important  researches  of  E.  and  O.Fischer, 
Rosenstiehl,  and  Dale  and  Schorlemmer,  have  proved  that  under  the 
name  rosanilin  have  been  included  both  isomeric  and  homologous  bases 
of  generally  similar  character,  and  Dale  and  Schorlemmer  have  shown 
that  of  these  para-rosanilin  with  the  formula  Cj^H^^Ng  (identical  with 
that  made  from  para-toluidin)  may  be  prepared  from  phenol,  by  con- 
verting this  into  aurin,  C^gH^^Og,  and  heating  the  latter  with  an  excess  of 
aqueous  ammonia;  while,  if  aurin  be  heated  with  anilin,  the  final  pro- 
duct is  tri-phenyl  para-rosanilin,  thus  establishing  full  connection 
between  phenol  and  the  whole  series  of  anilin  colors. 
The  original  anilin  violet  of  Hofmann,  obtained  by  the  methylation 
of  pre  formed  rosanilin  salts,  has  been  to  a  large  extent  replaced  by 
the  ''violet  de  Paris,"  made  by  first  heating  anilin  under  pressure  with 
methyl  chloride  or  methylic  alcohol  and  hydrochloric  acid,  thus  obtain- 
ing methylated  anilin  derivatives,  and  then  oxidizing  such  product  by 
iheatine^  it  in  the  air,  mixed  with  sand  and  a  salt  of  one  of  the  heavy 
