Am  Tour.  Pharm.1 
Feb.,  1877.  / 
Editorial. 
93 
Minims  and  Drops. — At  the  present  time,  when  the  introduction  of  the  metric 
system  of  weights  and  measures  is  so  widely  discussed  in  the  United  States,  ii 
becomes  of  importance  to  guard  against  erroneous  statements  gaining  a  foothold, 
which  might  prejudice  the  inexperienced  against  a  system  which,  after  its  successful 
introduction,  promises  to  be  of  such  great  advantage.  It  appears  to  have  escaped 
general  notice  that  the  two  tables  of  the  "  U.  S.  Pharmacopoeia  "  giving  the  rela- 
tion of  the  old  and  metric  weights  differ,  though  slightly,  in  the  value  of  the  gram,, 
which  difference,  however,  becomes  apparent  only  for  the  values  of  one  ounce  and 
over,  amounting  for  12  troyounces  to  less  than  4  centigrams,  quite  insignificant  in 
its  practical  bearing.  Different  values  are  again  given  in  a  paper,  the  original  of 
which  we  have  not  seen,  but  which  we  find  copied  in  the  "Virginia  Medical 
Monthly  "  for  December.  The  paper,  which  is  entitled  "  Practical  Illustration  of 
the  Metric  System,"  was  taken  from  the  "  Medical  Register  for  New  England,^ 
and  has  for  its  author  Francis  H.  Brown,  M.D.,  assisted  by  Dr.  Robt.  Amory,  of 
Brookline,  and  Prof.  G.  F.  H.  Markoe,  of  Roxbury.  The  most  conflicting  statements- 
are  given  as  to  the  relative  value  of  the  different  weights  and  measures,  as,  for  in- 
stance, the  gram  is  stated  in  two  contiguous  places  to  be  equal  to  15-4323  and  to 
15-4349  grains.  This  difference,  however,  does  not  vary  much  from  the  difference 
in  the  "Pharmacopoeia"  tables,  and  is  practically  of  no  account.  It  is  different,, 
however,  with  other  errors,  which  are  by  far  too  serious,  though  quite  inconsistent,, 
so  that  they  appear  to  demand  some  notice  here  by  placing  two  statements  side-by- 
side  : 
f3i=3"69  cubic  centimeters  ; — for  water  ^=60^  or  3  grams. 
Since  a  cubic  centimeter  of  water  at  its  greatest  density  (4°C.)  weighs  1  gram, 
the  incorrectness  of  the  above  statement  is  quite  apparent,  even  if  the  different 
gravity  of  water  at  the  medium  temperature  (i5°C.)  is  not  neglected. 
But  when  the  statement  is  made  that  there  is  no  relation  between  the  density  of  a 
fluid  and  the  weight  of  a  minim,  it  is  so  clearly  incorrect  that  it  should  need  no  re- 
futation. A  table  given  with  the  paper  makes  the  bold  statement  that  20  minims- 
of  chloroform  weigh  only  '370  gram,  or  about  one-third  of  the  asserted  weight  of 
water,  the  latter  being  in  reality  only  about  three-fifth  the  weight  of  the  former 
liquid,  though  not  as  given  in  the  table. 
It  was  found  that  the  table,  together  with  several  sentences  referring  to  it,  have 
been  taken  from  Dorvault's  "  TOfficine  "  (edit.  1872,  p.  190),  the  translator  having 
made  the  slight  (?)  mistake  of  translating  drop  (goutte)  by  minim.  Dorvault 
describes  several  dropping  glasses,  and  then  states  that  "  the  apparatus  is  considered 
adjusted  if,  at  i5°C,  20  drops  of  distilled  water  weigh  1  gram,  at  least  within  5 
centigrams."  The  following  is  the  approximate  weight  of  20  drops  of  different  liquids, 
at  a  temperature  near  i5°C.    (We  give  only  a  few  from  the  lengthy  table)  : 
Syrup  (3S°B.), 
11 1 1 
grams. 
Oil  of  peppermint, 
•400  grams. 
Ammonia  (23°B), 
•909 
«< 
Oil  of  turpentine, 
■385  " 
Glycerin, 
•837 
n 
Chloroform, 
•370  " 
Sulphuric  acid  (sp.  gr. 
1-84),  -700 
<( 
Absolute  alcohol, 
•311  " 
Croton  oil, 
•410 
(< 
Sulphuric  ether, 
•263  " 
