200  Influence  of  Pharmacists  on  Chemistry.  | J^-  f**Tm- 
workers  from  the  ranks  of  pharmacy,  whose  present  contribution 
to  chemical  science  are  cordially  recognized.  While  it  would  be 
invidious  to  attempt  to  select  names  in  this  connection,  I  will  only 
mention  two,  both  of  whom  are  well  known  to  us,  namely  Professor 
John  U.  Lloyd,  a  recognized  authority  on  plant  chemistry,  and  more 
recently  upon  colloid  chemistry  reactions,  and  Frederick  B.  Power, 
a  graduate  and  former  instructor  in  this  College,  who  is  recognized 
both  in  England  and  in  this  country  as  probably  the  first  authority 
upon  the  subject  of  essential  oils.  He  is  still  active  in  the  Govern- 
ment service  at  Washington  on  this  subject. 
The  direct  influence  of  pharmacists  on  the  creation  of  chemical 
industries  is,  however,  most  readily  illustrated  by  a  study  of  the 
history  of  the  development  of  manufacturing  chemical  industries 
in  this  city  of  Philadelphia,  which  has  been  known  for  many  years 
as  a  great  chemical  manufacturing  center,  and  I  will  therefore  in 
some  detail  review  the  development  of  Philadelphia's  chemical 
industries. 
"Probably  the  first  to  inaugurate  the  manufacture  of  chemicals, 
as  such,  in  this  country,  was  the  firm  of  Christopher,  Jr.,  and 
Charles  Marshall,  sons  and  successors  of  Christopher  Marshall,  an 
early  druggist  and  one  of  the  original  'fighting  Quakers'  of  Phila- 
delphia. This  firm  had,  as  early  as  1786,  entered  quite  extensively 
into  the  business  of  making  muriate  of  ammonia  and  Glauber's 
salt.  The  factory  is  described  by  Watson,  in  his  "Annals  of 
Philadelphia,'  as  being  a  grim  and  forbidding-looking  building  on 
Third  Street,  near  the  stone  bridge  over  the  Cohocksink  Creek. 
This  firm  is  said  to  have  developed  an  annual  output  of  upwards 
of  6000  lbs.  of  muriate  of  ammonia;  quite  an  achievement  for  that 
time." 
Let  us  now  take  up  the  beginnings  of  the  manufacture  in 
Philadelphia  of  one  of  the  fundamentally  important  chemicals,  viz., 
sulphuric  acid.  This  substance  is  recognized  as  the  basis  of  all 
chemical  industries  and  its  manufacture  must  precede  that  of  most 
other  chemicals.  The  theory  of  the  lead-chamber  process  was 
already  understood  by  chemists,  by  the  middle  of  the  eighteenth  cen- 
tury. Ward  had  made  it  in  England  in  1740  on  a  large  scale  in 
glass  vessels,  and  Dr.  Roebuck  first  used  leaden  chambers  instead 
of  glass  in  Birmingham  in  1746.  The  first  leaden  chamber  was 
erected  in  France,  at  Rouen,  in  1766. 
Mr.  John  Harrison,  the  son  of  Thomas  Harrison,  a  member 
