ON  SOME  POINTS  OF  CHEMICAL  THEORY,  ETC. 
393 
cinchona  trees  of  South  America  are  in  danger  of  being  wholly 
exhausted. 
When  we  consider  the  numerous  contributions,  made  by  chem- 
istry to  medicine,  in  the  form  of  some  of  our  most  valuable  reme- 
dies; and  when  we  reflect  that  the  future  is  as  likely  to  be  pro- 
lific in  chemical  discoveries  as  the  past,  we  cannot  fail  to  per- 
ceive, that  to  no  science  can  the  physician  or  pharmaceutist 
direct  his  attention  with  a  greater  prospect  of  enriching  the 
healing  art  than  to  chemistry.  The  medical  applications  of  the 
science  are  far  from  being  all  known.  Chemical  substances 
may  yet  be  discovered,  which  shall  rival,  as  therapeutic  agents, 
ether  and  chloroform.  The  practical  application  of  ether,  as  a 
means  of  abolishing  pain,  is  exclusively  an  American  discovery  ; 
and  the  subsequent  use  of  chloroform  for  the  same  purpose, 
is  only  making  a  second,  but  far  less  important  step  in  the  same 
direction.  Ether  is  a  safe  anaesthetic,  and  it  is  claimed  that 
chloroform,  ivhen  properly  used,  i3  safe  also.  Gregory  has 
asserted,  that,  in  Edinburgh,  where  chloroform  has  been  em- 
ployed in  more,  perhaps,  than  100,000  cases,  no  instance  of 
death  has  occurred  from  its  use ;  and  he  attributed  the 
fatal  cases  that  have  taken  place  elsewhere,  either  to  the  use  of 
impure  chloroform,  to  the  unfitness  of  the  cases  in  which  it  was 
employed,  or,  finally,  to  the  administration  of  an  over-dose. 
The  question  of  the  comparative  merits  of  ether  and  chloroform 
as  anesthetics  is  a  practical  one,  and  must  be  decided  in  favor 
of  ether  ;  for,  while  safety  requires  that  certain  precautions 
shall  be  observed  in  giving  chloroform,  the  neglect  of  these  is 
attended  with  little  or  no  danger  in  administering  ether. 
Chemistry  has  thrown  an  important  light  on  certain  dietetic 
articles,  which  are  used  by  all  civilized  nations,  and,  after  hav- 
ing been  once  adopted  by  them,  have  never  been  known  to  be 
laid  aside.  I  allude  to  coffee  and  tea,  and  to  the  Paraguay  tea 
and  guarana  of  South  America.  The  instinct  of  the  human 
stomach,  it  wTould  seem,  leads  different  nations  to  adopt  these 
substances  as  a  drink ;  they  being  valued  for  their  invigorating 
and  refreshing  qualities.  The  most  enlightened  nations  employ, 
for  the  most  part,  coffee  and  tea ;  and,  if  our  best  writers  were 
willing  to  own  it,  they  would  acknowledge  their  obligations,  for 
much  of  their  inspiration,  to  these  beverages.  Now,  all  these 
substances  contain  the  same  essential  principle,  namely,  caf- 
