Am.  Jour.  Pharm. 
Feb.  ,1889. 
Photography. 
99 
evident  from  this  that  the  solvent  action  of  the  alcoholic  medium  is 
quite  sufficient  to  hold  the  morphine  in  solution.  Although  these  re- 
sults are  of  a  negative  character,  they  are  well  worth  recording,  as  no 
doubt  others  have  observed  this  crystalline  deposit  and  have  possibly 
come  to  the  same  conclusion  as  myself,  and  they  also  show  that  the 
Formulary  Committee  have  been  well  advised  in  directing  the  lini- 
ment to  stand  a  week  before  filtering. — Phar.  Jour,  and  Trans.,  Dec. 
1,  p.  442. 
RECAMIER  TOILET  POWDER. 
"  Guaranteed  free  from  lead,  bismuth  and  arsenic.  The  finest  pow- 
der ever  manufactured.    Will  not  make  the  face  shine." 
Sample  packages  of  this  powder  have  been  distributed  by  mail.  A 
chemical  and  microscopical  investigation  of  the  preparation  shows  its 
composition  to  be  oxide  of  zinc  mixed  with  starch. 
C.  B. 
PHOTOGRAPHY. 
BY   F.    V.  BUTTERFIELD. 
{Continued  from  page  48.) 
The  result  of  all  this  work  is  a  negative,  from  which  as  many  copies  as 
required  may  be  taken  by  the  process  of  printing.  The  conventional  term 
"  negative  "  may  possibly  puzzle  some,  so  I  will  just  explain  en  passant  that 
it  is  so  called  in  contradistinction  to  a  "positive,"  which  is  a  picture  in  it- 
self, whilst  a  "  negative"  is  only  the  means  of  making  one;  in  the  latter  all 
the  lights  and  shades  are  reversed ;  it  is  always  examined  by  transmitted 
light,  the  former  by  reflected  light. 
As  stated  in  a  previous  portion  of  this  paper,  wet-plate  photography  seems 
well  adapted  for  taking  "  positives,"  and  the  peripatetic  photographer,  a  well- 
known  character  in  all  popular  places  of  resort,  does  not  by  any  means  lose 
sight  of  this.  Another  common  form  of  the  collodion  positive  is  the  ferro- 
type, possibly  familiar  to  you  under  the  name  of  'American  Gem  "  por- 
traits, the  only  difference  being  in  the  substitution  of  a  thin  sheet  of  enam- 
elled iron  for  the  ordinary  glass  plate. 
The  gelatin-bromide  process  is  similar  in  principle  to  the  above,  but 
here  gelatin  is  used  in  the  place  of  collodion  for  holding  the  sensitive  sil- 
ver salts  in  situ,  the  advantage  being  that  the  plates  can  be  prepared  a  great 
length  of  time  before  using ;  and  also  after  exposure,  they  may  be  kept  for  a 
lengthened  period,  prior  to  development,  a  fact  of  no  little  importance, 
when  on  a  tour  abroad,  for  instance  ;  but  the  most  striking  feature  in  con- 
nection with  its  use  is  that  the  gelatin  in  some  way  or  other  appears  to  act 
