ADDRESS. 
195 
It  has  been  elsewhere  said,  that  the  three  primary  duties  of 
the  pharmaceutist  are  "  to  procure  and  keep  good  drugs  ;"  "to 
prepare  from  these  efficient  and  uniform  medicines  ;"  and  "to 
dispense  these  medicines  to  the  sick,  in  a  perfect  condition." 
To  perform  the  first  of  these  judiciously,  the  apothecary  must 
know  the  nature  and  qualities  of  drugs,  their  tendency  to  de- 
teriorate by  age  and  exposure,  the  means  of  preserving  them  in 
the  best  manner,  and  lastly,  he  must  conscientiously  practice 
what  he  knows,  the  most  difficult  and  often  the  least  appreciated 
portion  of  his  duty. 
The  study  of  drugs  involves  much  scientific  knowledge,  leads 
the  student  into  botany,  mineralogy  and  other  branches  of  na- 
tural history,  and  chemistry  is  largely  concerned  in  judging  of 
their  quality.  He  will  often  observe  an  adaptation  of  means  to 
ends  in  the  production  of  medicinal  substances,  not  less  wonder- 
ful than  in  other  results  of  creative  power.  The  bark  of  the 
wild  cherry  tree  is  highly  prized  by  the  physician,  for  a  remark- 
able association  of  tonic  and  sedative  powers,  extremely  useful 
in  pectoral  and  cardiac  diseases.  The  principal  upon  which 
this  sedative  influence  depends  is  prussic  acid ;  the  same  vola- 
tile, evanescent  substance,  which,  when  made  by  the  chemist,  is 
so  powerful  a  poison  ;  and  which,  did  it  exist  ready  formed  in 
the  bark  when  gathered,  would  soon  evaporate  and  leave  it  near- 
ly worthless  on  drying.  But  so  useful  a  drug  has  not  been  left 
liable  to  certain  deterioration  ; — stored  safely  in  the  tissues  of 
the  bark  are  two  distinct  substances,  neither  of  which  is  the 
medicinal  acid,  but  when  they  come  together  in  the  presence  of 
water,  a  chemical  reaction  occurs,  and  from  the  twain  comes  the 
valuable  sedative  full  of  healing  power.  It  has  been  shown  by 
one  of  your  predecessors,  that  the  value  of  this  bark  varies  with 
the  season  of  its  collection,  having  double  the  strength  in  Octo- 
ber that  it  has  in  May  ;  and  the  well-informed  apothecary, 
knowing  this,  avoids  gathering  the  drug  in  the  spring  or 
summer. 
The  trees  producing  the  Peruvian  bark  are  found  on  the 
eastern  slopes  of  the  South  American  Andes,  stretching  from 
near  the  Caribbean  Sea  to  the  Bolivian  Republic,  growing  at  an 
elevation  varying  from  5000  to  9000  feet  above  the  level  of  the 
sea.  Many  species  of  this  tree  exist,  yielding  barks  of  various 
quality  and  medical  value ;  some  containing  much  quinine, 
