Am.  Jour.  Pharm. ) 
March,  1889.  J 
Photography. 
155 
dextro-rotation  exercised  by  the  liquid.  The  quantity  of  the  amyl  ni- 
trites contained  in  the  original  substance  was  about  50  per  cent. 
A  specimen  obtained  from  another  well-known  maker  had  evi- 
dently been  prepared  from  very  imperfectly  rectified  fusel  oil,  and  in 
all  probability  by  the  action  of  nitric  acid.  When  half  a  litre  was 
fractionally  distilled  a  liquid  was  obtained  at  20°  which  after  redistilla- 
tion proved  to  be  chiefly  ethyl  nitrite  (b.  p.  17°).  Liquid  distilled  at 
all  temperatures  between  20°-55°  and  at  55°,  65  cc.  had  been  ob- 
tained. This  fraction,  when  submitted  to  redistillation,  yielded  prim- 
ary propyl  nitrite.  Between  55°-70°  53  cc.  of  liquid  passed  over, 
and  after  this  had  been  many  times  fractionally  redistilled  iso-butyl 
nitrite  (b.  p.  67°)  was  obtained.  Between  70°-80°  60  cc.  distilled 
and  between  80°-90°  35  cc.  By  distilling  these  fractions,  together 
with  residues  from  the  distillation  of  lower  fractions,  a  mixture  of 
a-amyl  nitrite  and  6-amyl  nitrite  boiling  at  96°  was  isolated.  It  was 
shown  by  analysis  to  be  almost  pure  (0*211  gram,  of  liquid  yielded  an 
amount  of  nitric  oxide  equivalent  to  0*2109  gram,  of  C5HnN02).  By 
continuing  the  fractional  distillation  about  50  per  cent,  of  liquid  was 
collected  above  100°.  In  this  liquid  were  recognized  unaltered  amyl 
and  other  homologous  alcohols,  valeric  acid  and  amyl  valerate,  but  it 
was  not  minutely  examined.  The  total  amount  of  the  amyl  nitrites 
obtained  constituted  less  than  40  pec  cent,  of  the  original  liquid. 
Professor  Cash  has  observed  that  pure  iso-butyl  nitrite  acts  more 
powerfully  than  the  mixture  which  constitutes  the  official  "  amyl  ni- 
trite." 
We  wish  to  thank  Miss  L.  E.  Boole  and  Mr.  Frank  Browne  for 
having  confirmed,  by  an  independent  series  of  experiments,  the  re- 
sults which  are  recorded  in  this  paper. — Phar.  Jour,  and  Ivans.,  Dec. 
22,  1888,  p.  489. 
PHOTOGRAPHY. 
BY   F.  V.  BUTTERFIELD. 
{Continued  from  page  103.) 
The  first  thing  required  in  the  silver  salt  process  is  some  ready -sensitized 
albumenized  paper ;  this  can  now  be  bought  very  cheaply,  and  consists  of 
paper  coated  on  one  side  with  egg-albumen,  containing  also  in  its  solution 
a  certain  amount  of  ammonium  chloride.  When  dry  it  is  sensitized  by 
floating  it  on  a  bath  of  silver  nitrate  (made  also  of  a  particular  strength), 
the  chloride  and  silver  nitrate  of  course  at  once  reacting,  the  change  being 
expressed  by  the  equation— NH4Cl+AgN03=AgCl+NH4N03. 
