5,460,919  7  8  The dye  or the  pyridinium  salt  derivative  for use in  this  invention  can be added  thereto  at any  desired step  during the  production  of the silver  halide  photographic  material.  For  example,  in the case  of adding  to the  negative-working  silver  halide emulsion,  the  compound  can be added  thereto  at an  optional  time from  the  initiation  of the  chemical  ripening  of  In  formula  (N-III), R$_{6 }$ represents  an alkyl  group (such  as  methyl,  ethyl, propyl,  butyl, pentyl,  etc.) or  a  substituted  alkyl group;  said  R$_{6 }$ may form  a  6-membered  ring or a  5-membered  ring  together  with  R$_{8}$ ;  R$_{7 }$ represents  a  hydrogen  atom, an  alkyl group  (such as  methyl, ethyl,  propyl, butyl,  pentyl, etc.),  a  substituted  alkyl group,  or an aryl  group (such  as  phenyl,  alkyl-substituted  phenyl, etc.).  As the  substituent  of the  substituted  alkyl group  shown by  R$_{6 }$ and  R$_{7}$ ,  there are,  for  example,  a  hydroxy  group, an  alkoxy group  (such as  methoxy,  ethoxy, etc.),  and an aryl  group (such  as  phenyl,  alkyl-substituted  phenyl,  etc.). Specific  examples  of the  substituted  alkyl group  are  2-hydroxyethyl,  3-hydroxypro› pyl,  2-methoxyethyl,  2-ethoxyethyl,  3-methoxypropyl,  ben› zyl, and  2-phenylethyl.  R$_{8 }$ and  R$_{9 }$ each  independently  rep- resents  a  hydrogen  atom, an  alkyl group  (such  a  methyl,  ethyl, propyl,  etc.), an  alkyl group  substituted  with a  For adding  the dye or  the  pyridinium  salt  derivative  for  use in this  invention  to the  negative-working  silver halide  emulsion  layer or  the other  light-insensitive  hydrophilic  colloidal  layer, the  dye or the  pyridinium  salt  derivative  may  be added  to the  negative-working  silver halide  emulsion  or  an  aqueous  solution  of a  light-insensitive  hydrophilic  colloid  for use in  this  invention  as a  solution  thereof  in water  or an  organic  solvent miscible  with water,  such as  alcohols,  ketones,  esters, amides,  etc.  Also, the  dyes and  the  pyridinium  salt  derivatives  for use  in the  present invention  can be used  singly or  as a  combi› nation of  them.  The addition  amount  of the dye  and the  pyridinium  salt  derivative  to the silver  halide  photographic  material  is  suitable  in the range  of from lxl0- $^{6 }$mo! to JxJ0- $^{2 }$mo! per  mo! of silver  halide, and  in the case  of adding  the dye alone,  the  amount  is  preferably  from Jx10- 3  mo! to lxJ0- 1  mo!,  and in the  case of the  pyridinium  salt  derivative  alone, the  amount  is  preferably  from lx!0-4  mo! to lxJ0- 2  mo!, and  when  a  polyalkylene  oxide or  the  derivative  thereof (here› inafter, they  are  referred  to as  simply  polyalkylcne  oxide  derivatives)  exists, the  amount  of the dye  or the  pyridinium  salt  derivative  is  particularly  preferably  from lx!0- $^{5 }$mo! to  lx10- 3  mo!.  The  foregoing  dye or  pyridinium  salt  derivative  for use in  this  invention  can contain  in at least  one  negative-working  silver halide  emulsion  constituting  the silver  halide photo- graphic material  or other  light-insensitive  layer  composed  of  a  hydrophilic  colloidal  layer such  as a  protective  layer, an  interlayer,  an  antihalation  layer,  a filter layer,  etc.  These  pyridinium  salt  derivatives  can be  synthesized  by  reacting  corresponding  pyridine  derivatives,  quinoline  derivatives,  or  isoquinoline  derivatives  and alkyl  halides  as  described  in  Munio Kotake,  Dai Yuuki  Kagaku  (Principal  Organic  Chemistry),  Vol. 16,  (III), pages  7 and 125,  pub- lished by  Asakura  Shoten, 1959.  Practical  synthetic  methods  of them  are  described  in A. Grob  and E. Renk,  Helv. Chim.  Acta.,  37,  1672(1954);  R.  E. Lyle,  E.  F.  Perlowski,  H.  J.  Troscianiec,  and G. G.  Lyle,  J.  Org. Chem.,  20,  1716(1955);  M. R.  Lamborg,  R.  M.  Burton,  and N.  0.  Kaplan,  J.  Am.  Chem. Soc.,  79,  6173(1957);  and  W.  Ciusa and  A.  Buccelli,  Gazetta  Chimia Italiana,  88,  393(1958).  In  formula  (N-II),  R$_{3 }$ represents  an  unsubstituted  alkyl  group or  an alkyl  group  substituted  preferably  with a  hydroxy  group, an  alkoxy group  such as  methoxy,  ethoxy,  etc., an  aromatic  group such  as  phenyl, etc.,  an acyl group  such as acetyl,  benzoyl,  etc., an  alkoxycarbonyl  group such  as  methoxycarbonyl,  ethoxycarbonyl,  etc., an amide  group,  a  cyano group,  etc.  Practical  examples  of R$_{3 }$ are  methyl,  ethyl, n-propyl,  isopropyl,  n-butyl,  isobutyl,  pentyl, 2-hy› droxyethyl,  3-hydroxypropyl,  2-methoxyethyl,  3-ethox› ypropyl,  2-phenylethyl,  3-acetylpropyl,  2-benzoylethyl,  2-methoxycarbonylethyl,  2-cyanoethyl,  and  2-carbamoyl› ethyl.  R$_{4 }$ and R$_{5 }$ each  independently  represents  a  halogen  atom, an  alkyl group  (e.g., methyl,  ethyl, n-propyl,  isopro› pyl, n-butyl,  isobutyl,  and pentyl),  a  substituted  alkyl group,  or an  alkoxy group  (e.g., methoxy  and ethoxy).  As the  substituent  for the  substituted  alkyl group  described  above,  a  hydroxy  group, an  alkoxy group,  and a  substituted  or  unsubstituted  aromatic  group (e.g.,  phenyl and  alkyl-substi› tuted phenyl)  are  preferable.  Also, practical  examples  of the  substituted  alkyl group  are  hydroxymethyl,  2-hydroxyethyl,  3-hydroxypropyl,  2-methoxyethyl,  2-ethoxyethyl,  benzyl,  2-phenylethyl,  and  2-tolylethyl.  n2 and n3  each indepen› dently represents  0, 1, or  2.  When plural  R$_{4}$s  and/or  R$_{5}$s  exist, they  may be the  same or  different.  x- represents  an  anion as  an iodine  ion, a  bromine  ion, a chlorine  ion, a  p-toluenesulfonic  acid ion,  a  perchloric  acid ion,  a  methyl› sulfuric  acid, etc.,  but when  formula  (N-II)  is a  betaine  structure,  X $^{31 }$does not  exist.  Then, specific  examples  of the  pyridinium  salt  derivatives  for use in  the present  invention  are  illustrated  below but  the  invention  is not  limited  to those  compounds.  t,0420  hydroxy  group, an  alkoxy group,  an  aromatic  group, etc.,  (such as  2-hydroxyethyl,  3-hydroxypropyl,  2-methoxyethyl,  3-ethoxypropyl,  benzyl,  2-phenylethyl,  etc.), an  alkoxy  group (such  as  methoxy,  ethoxy, etc.),  or an amide  group.  Furthermore,  R$_{8 }$and  R$_{9 }$ may form  together  an  aromatic  ring.  R$_{10 }$ represents  a  halogen  atom  (chlorine,  bromine,  etc.), an  alkyl group  which may  be  unsubstituted  or  substituted  (such  as  methyl, ethyl,  propyl,  2-hydroxyethyl,  3-hydroxypropyl,  2-methoxyethyl,  benzyl,  etc.), an  alkoxy group  (such as  methoxy,  ethoxy, etc.),  or an amino  group which  may be  substituted  with an alkyl  group. Also,  n4  represents  0, 1, or  2.  When plural  R$_{10}$s  exist, they  may be the  same or different.  X $^{31 }$represents  an anion  such as an  iodine ion,  a  bromine  ion,  a  chlorine  ion, a  p-toluenesulfonic  acid ion,  a  perchloric  acid  ion, a  methylsulfuric  acid ion,  etc., but  when formula  (N-III)  is a  betaine structure,  X$^{31 }$does not  exist.  Also, in  formula  (N-I)  and formula  (a),  R$_{2 }$ represents  an  alkyl group  (methyl,  ethyl, propyl,  butyl, etc.),  an alkyl  group  substituted  with a hydroxy  group, an  alkoxy group,  or  an  aromatic  group such  as  phenyl,  pyridyl,  etc., [e.g.,  2-hydroxyethyl,  3-hydroxypropyl,  2-methoxyethyl,  4-ethoxybutyl,  benzyl,  2-phenylethyl,  and  3-(4-pyridyl)pro› pyl], or an  amide group  (such as  -CONH$_{2}$ ,  -CONHCH$_{3}$ ,  etc.); nl  represents  O  or an  integer  of from  1 to 3; when  plural  R$_{2}$s exist, they  may be the  same or  different;  and X 31  represents  an anion  such as an  iodine ion,  a  bromine  ion, a  chlorine  ion, a  p-toluenesulfonic  acid ion,  a  perchloric  acid  ion, a  methylsulfuric  acid ion,  etc., but  when formula  (N-I)  is a  betaine structure,  X 31  does not  exist.  N,N-dimethylamino,  etc.), an  aromatic  group such  as phe› nyl, pyridyl,  etc., or  -A-Z  (wherein  A  represents  an  alkylene  group having  from 1  to 20  carbon atoms  or  CH$_{2}$ CH=CHCH$_{2 }$ and Z  represents  a  hydrogen  atom, a  phenyl group  which may  be  unsubstituted  or  substituted,  a  hydroxy  group, an  alkoxy group  such as  methoxy,  ethoxy,  etc., an  acyl group  such as benzyl,  acetyl, etc.,  an  alkoxy› carbonyl  group such  as  methoxycarbonyl,  ethoxycarbonyl,  etc., a cyano  group, an  N-alkylamide  group, an  amide group,  or a group  shown by  formula  (a)  described  above. 