46 
Pharmaceutical  Study. 
/Am.  Jour.  Pharm. 
1       Jan.,  1886. 
tary  structure  and  arrangements  of  parts  in  the  vegetable  kingdom  is  this,  that 
we  have  tangible  objects  to  deal  with  here,  which  can  be  brought  within  the 
cognizance  of  our  senses.  We  can  dissect,  divide  and  subdivide  them,  and  when 
we  have  thus  passed  to  the  limit  of  observation  by  the  unaided  organs  of 
vision,  we  can  resort  to  the  powers  of  the  micro -cope  and  thus  open  out  ex- 
tended fields  for  farther  investigation.  The  knowledge  we  thus  acquire  is  of 
a  definite  and  definable  nature.  There  is  n  >thing  speculative  about  it.  It  par- 
takes not  of  the  abstract,  but  of  the  concrete  character. 
Botany  has  become  a  necessary  adjunct  to  materia  medica,  and  the  two  sub- 
jects are  more  or  less  intimately  associated  when  studied  for  medical  or  phar- 
maceutical purposes. 
Chemistry,  in  like  manner,  has  become  an  adjunct  to  pharmacy,  and,  also, 
although  in  a  lesser  degree,  to  materia  medica.  As  the  use  of  substances  of  a 
definite  .chemical  na  ure  has  become  fully  established  in  medical  practice,  and 
the  number  of  medicines  of  that  description  has  undergone,  and  is  farther 
likely  to  undergo,  considerable  augmentation,  chemistry  is  even  more  neces- 
sarily allied  to  pharmacy  than  botany  is  to  materia  medica.  The  study  of 
chemistry  forms  the  most  important  part  of  pharmaceutical  education,  and  one 
which  admits  of  great  and  most  usefal  extension.  Taken  in  its  fullest  signifi- 
cation, the  scope  of  chemistry  is  more  vast  and  comprehensive  than  even  that 
of  b  >tany,  for  while  the  latter  comprehends  only  one  of  the  three  kingdoms  of 
nature,  chemis!ry  takes  cognizance  of  all  three.  It  treats  not  of  the  physical 
structure,  bat  of  the  elementary  composition  of  b  jdies  and  of  all  bodies.  The 
range  of  its  comprehensive  applica'ion  extends  even  beyond  the  earth  and  its 
surroanding  atmosphere.  Every  material  object  is  compos-d  of  parts  having 
a  chemical  constitution,  and  this  is  subject  to  chemical  change.  It  is  the  prov- 
ince of  the  chemist  to  investigate  such  changes,  and  to  trace  out  the  component 
parts  of  all  objects,  but  we  cannot  do  this  in  the  way  in  which  we  trace  out  the 
structure  and  arrangement  of  parts  of  a  plant.  We-  cannot  say  of  the  matter 
of  which  chemistry  treats  that  it  consists  of  parts,  or  atoms,  or  molecules  that 
are  tangible,  visible,  or  definable  as  to  structure.  We  may  know  them  in  the 
aggregate,  but  of  the  individual  parts  our  knowledge  is  indefinite  and  specula- 
tive. What  do  we  know  of  any  chemical  element  or  compound?  Of  oxygen, 
or  water,  or  alcohol,  for  instance?  We  know  oxygen  as  a  gas,  and  may  acquire 
some  knowledge  of  it  in  a  more  condensed  form,  but  wrhat  do  we  know  of  its 
ultimate  particles  or  atoms,  of  their  form,  size,  or  weight?  So  also  with  regard 
to  water,  a  Chemical  compound  of  ogygen  with  another  element,  or  alcohol  or 
acetic  acid,  compounds  of  oxygen  with  two  other  elements.  We  have  a  certain 
concrete  knowledge  of  them ;  we  know  them  in  the  aggregate,  but  beyond  that 
we  enter  the  region  of  speculation.  Our  knowledge  leads  us  to  the  conclusion 
that  water  is  a  chemical  compound  of  oxygen  and  hydrogen.  But  what  do  we 
mean  by  a  chemical  compound  of  elements?  It  does  not  simply  mean  that 
the  elements  are  brought  together,  intimately  mixed,  and  in  contact.  We  may 
to  that  extent  put  oxygen  and  hydrogen  together  in  the  definite  proportions  in 
which  they  combine,  but  that  does  not  necessarily  involve  combination ;  and 
when  they  are  combined  what  is  the  nature  of  their  altered  condition,  and  what 
are  the  positions  and  distribution  of  the  respective  atoms  or  particles?  We  are 
accustomed  to  represent  the  elements  by  symbols,  and  to  represent  chemical 
compounds  by  placing  the  symbols  in  juxtaposition,  or  by  connecting  them  in 
