Am.  Jour.  Pharm. 
May,  1884. 
Life  of  Robert  Bridges,  M.  D. 
243 
eminent  medical  teacher  and  surgeon  nearly  four  years.  He  had  asso- 
ciated with  him,  in  teaching  his  large  class  of  students,  several  assist- 
ants. His  office  was  a  two-storied  house,  on  the  north  side  of  Library 
street,  near  to  Fourth  street.  In  it  were  a  students'  reception-room,  a 
laboratory  and  a  lecture-room,  and,  in  the  rear  of  the  house,  a.  dissect- 
ing-room. In  Dr.  Hewson's  private  medical  school  Dr.  Franklin 
Bache  taught  chemistry.  He  appointed  young  Bridges  his  assistant 
very  soon  after  he  began  his  medical  studies.  In  this  capacity  he 
served  Dr.  Bache  through  many  years  in  the  courses  of  chemical  lec- 
tures delivered  by  him  in  the  Franklin  Institute,  in  the  Philadelphia 
College  of  Pharmacy,  and  at  the  Jefferson  Medical  College.  This 
practical  training  made  him  an  expert  chemist  and  an  admirable 
teacher  of  chemistry. 
His  close  attention,  habitually  given  to  whatever  he  might  be  doing, 
qualified  him  in  a  high  degree  to  assist  the  lecturer  on  chemistry.  In 
May,  1827,  upon  pouring  water  into  an  iron  mercury  flask,  which  had 
been  used  for  obtaining  oxygen  from  nitre,  for  the  purpose  of  washing 
it,  he  noticed  a  lively  effervescence.  He  proceeded  at  once  to  investi- 
gate the  nature  of  the  gaseous  matter,  and  found  it  to  consist  of  oxy- 
gen of  a  purity  of  ninety-five  per  cent.,  as  he  ascertained  by  Dr.  Hare's 
accurate  sliding- rod  eudiometer.  He  observed  the  same  phenomenon, 
November  27,  at  the  Franklin  Institute,  and  found  in  this  instance 
that  the  oxygen'  contained  only  one  per  cent,  of  impurity.  He  sug- 
gested that  this  residuum,  which  Dr.  Hare  conjectured  to  be  peroxide 
of  potassium,  would  furnish  pure  oxygen  to  the  experimenter  without 
trouble.  He  was  anticipated  in  this  discovery.  Mr.  Richard  Philips, 
of  London,  had  made  the  same  observation  and  given  the  same  ratio- 
nale of  the  phenomenon,  an  account  of  which  he  published  in  the 
"Annals  of  Philosophy"  for  April,  1827.  Nevertheless,  Dr.  Frank- 
lin Bache  published  in  the  "  North  American  Medical  and  Surgical 
Journal"  for  January,  1828,  a  note  of  the  observation  of  "Mr.  Robt. 
Bridges,  student  of  medicine,"  on  the  Residuum  of  Nitre  after  Expo- 
sure to  Red  Heat."  The  circumstance  indicates  his  character  as  a 
student,  and  at  the  same  time  Dr.  Bache's  kind  appreciation  of  his 
worth. 
Dr.  Bridges  graduated  from  the  medical  department  of  the  Univer- 
sity of  Pennsylvania,  March,  1828.  "Neuralgia"  was  the  subject  of 
his  thesis.  He  immediately  opened  an  office  at  the  southeast  corner  of 
Vine  and  Thirteenth  streets,  where  he  remained  till  1837.    He  did 
