Am.  Jour.  Pharm. 
Jan.,  1889. 
Photography. 
45 
PHOTOGRAPHY. 
BY  F.  V.  BUTTERFIELD.1 
With  the  exception  of  a  short  and  succinct  historical  account,  and  a  few 
necessary  remarks  on  its  relation  to  light  and  chemistry,  I  shall  devote  the 
best  portion  of  this  paper  to  the  more  important  details  and  modus  operandi 
of  that  branch  popularly  known  as  "  amateur  photography,"  so  that  any 
who  are  desirous  of  taking  up  this  fascinating  pursuit  may  be  able  to  do  so 
with,  I  hope,  facility  and  ease.  At  the  same  time,  however,  others  who 
cannot,  for  various  reasons,  take  up  the  practice  of  photography  for  pleas- 
ure, or  who  rather  choose  to  "scorn  delights  and  live  laborious  days,"  will 
find,  I  am  quite  sure,  a  slight  acquaintance  with  this  subject  either  useful 
from  a  business,  or  interesting  from  a  scientific  point  of  view,  for,  disre- 
garded as  a  work  of  art,  but  looking  at  it  solely  from  a  scientific  standpoint 
a  photograph  may  be  considered  simply  as  the  result  of  a  series  of  very 
delicate  chemical  reactions. 
Boasting  of  barely  half  a  century's  existence,  photography  has  made 
such  rapid  and  gigantic  strides  that  the  position  it  holds  to-day  is  one  of 
the  highest  importance.  Reverting  to  the  details  of  its  discovery  we  first  of 
all  find  the  old  alchemists  in  the  sixteenth  century,  whilst  engaged  in  their 
mysterious  craft,  puzzling  over  the  change  they  observed  took  place  when 
silver  chloride,  or,  as  they  termed  it,  luna  cornua,  was  exposed  to  the  light, 
and  which,  they  eventually  decided,  must  be  due  to  a  kind  of  transmutation 
of  metals,  a  conclusion  drawn  very  possibly,  I  think,  from  the  philosopher's 
stone  point  of  view,  which  when  discovered  would  in  some  such  simple 
manner  "  transmute"  all  the  baser  metals  into  gold. 
The  matter  remains  in  statu  quo,  until  another  century  "  has  dragged  its 
slow  length  along,"  when  history  records  that  this  phenomenon  attracted 
the  attention  of  one — Robert  Boyle — the  most  learned  philosopher  of  his 
time,  and  which  he  finally  settled  to  his  own  satisfaction  must  perforce  be 
caused  by  the  action  of  the  air,  "  sed  de  mortuis  nil  nisi  bonum."  He 
lived  in  dark  days,  when  chemistry  as  a  connected  science  could  hardly  be 
said  to  exist. 
The  question  once  more  lapses  for  a  long  period  into  a  state  of  quiescence, 
until  at  length  Scheele,  whose  name  is  well  known  to  all  of  you,  appears 
upon  the  scene,  deeply  interested  in  and  trying  to  solve  this  very  problem, 
but  although  he  succeeded  in  proving,  by  various  means,  that  it  was  really 
owing  to  a  reduction  of  the  silver  chloride,  with  partial  loss  of  chlorine,  his 
researches  proved  of  little  practical  utility  at  the  time. 
Years  roll  on,  iodine  and  bromine  have  both  been  discovered  and  found 
to  give  salts  of  silver  much  more  sensitive  to  the  light  than  the  old  chlor- 
ide; in  fact,  on  all  hands  we  find  the  enthusiastic  army  of  workers  in  this 
scientific  research  ever  increasing  and  bringing  matters  gradually  to  a  climax, 
which  at  last  took  place  in  1839,  a  year  ever  memorable  in  the  annals  of  photo- 
l  Read  before  the  Chemists'  Assistants'  Association,  London,  November  29th;  re- 
printed from  Phar.  Jour,  and  Trans.,  December  15th. 
