Am"oJc0",r,i8Aarm'}     Metrical  Weights  in  Prescriptions.  457 
THE  USE  OF  METRICAL  WEIGHTS  IN  PRESCRIPTIONS. 
BY  PROFESSOR  JOHN   M.  MAISCH, 
Of  the   Philadelphia  College  of  Pharmacy. 
The  desirability  of  uniform  values  of  the  weights  and  measures  in 
use  among  civilized  nations,  and  the  admirable  simplicity  of  the  French 
or  metrical  system,  are  so  apparent  that  this  standard  is  now  not  merely 
legalized,  but  has  been  adopted,  and  is  actually  used,  by  a  large  major- 
ity of  the  nations  of  Continental  Europe.  The  inconveniences  attend- 
ing such  a  change  are  more  due  to  the  alteration  .of  values  than  to  the 
introduction  of  the  system  with  which,  through  the  Arabic  numera- 
tion, every  one  is  familiar,  and  the  practical  application  of  which  we 
have  in  our  monetary  system.  The  intimate  acquaintance  with  the 
latter  must  doubtless  facilitate  the  comparison  of  values,  the  multiples 
and  divisions  of  which  are  based  upon  the  same  system  of  decimal 
numeration.  While  the  general  introduction  of  the  metrical  system 
in  the  United  States  must  be  regarded  merely  as  a  question  of  time,  it 
cannot  be  denied  that  considerable  progress  toward  this  end  would 
have  been  made,  if,  in  accordance  with  a  resolution  passed  by  the  Na- 
tional Convention  of  1870,  for  revising  the  "  Pharmacopoeia,"  the 
Committee  of  Revision  had  "abandoned  in  the  c  Pharmacopoeia ' 
measures  of  capacity,  and  expressed  the  quantities  in  all  formulas,  both 
in  weights  and  in  parts  by  weight."  Coupled  with,  the  direction,  "  to 
include  some  part  of  the  metrical  system  in  the  list  of  officinal  weights 
and  measures,"  the  parts  by  weight  could  scarcely  have  been  expressed 
otherwise  than  upon  the  basis  of  the  metrical  system. 
The  different  value  of  the  grain1  as  formerly  used  occasioned  many 
difficulties  in  adapting  formulas  and  doses  to  the  weights  of  other 
countries  ;  and  for  similar  reasons  the  use  of  local  values  in  measures 
and  weights  have  long  since  been  abandoned  in  all  physical  sciences, 
in  favor  of  the  metrical  system.  Medicine  and  pharmacy  only  lagged 
behind  until  a  few  years  ago,  when  it  was  adopted  also  in  the  two 
branches  named  by  nearly  all  civilized  nations,  except  those  speaking 
the  English  tongue,  and  the  labor  of  translating  the  values  contained 
in  formulas  and  prescriptions  is  now  almost  exclusively  confined  to  the 
systems  of  the  troy  weight,  and  the  English  and  American  apotheca- 
ries' measures,  as  arraigned  against  the  metrical  weight. 
1  The  variation  from  our  troy  grains  ranged  in  different  countries  between  — n 
and  -f*  46  per  cent. 
