380 
Drops  as  Dose  Measures. 
( Am.  Jour.  Pharm. 
1      August,  1902. 
being  "the  largest  drop  of  distilled  water  readily  obtained  from  any 
available  surface,  more  than  5  mm.  in  diameter,  dropping  not  slower 
than  1  drop  a  second." 
Another  advantage  to  be  found  in  accepting  this  low  number  of 
drops  as  a  popular  equivalent,  would  be  the  placing  of  all  possible 
error  on  the  side  of  safety. 
,  The  following  tables  illustrate  a  series  of  experiments  that  were 
made  with  different  dropping  surfaces,  in  everyday  use,  with  the 
object  of  determining  their  probable  average  and  their  possible 
variation.  In  this  connection  the  writer  would  also  call  attention  to 
the  table  on  page  133  (A.  J.  P.,  1502),  mentioned  above. 
TABLE  NO.  3. — NUMBER  OF  DROPS  OF  DISTILLED  WATER  THAT  WERE 
REQUIRED  TO  WEIGH  I  GRAMME,  DROPPED  IN  SECONDS,  FROM 
THE  SURFACES  INDICATED. 
Diameter  of     Number  ol 
Neck  of  Drops. 
Bottle.         Low.  High. 
9  to  12 
9  "  11 
50  "   
 24 
10  "  14 
 26  " 
9  -  11 
150  ■"  "  
 28  " 
9  "  12 
.....  .-29  " 
9  "  11 
......  32  " 
11  "  13 
11  "  13 
2  "       "         "  "  
 34  " 
15  "  15 
 38  . 
9  "  12 
16  "         "         "  "   
 42  " 
9  «'  11 
32   "         «         "         "          •    '.    •    •  • 
.  .  ...  .49  " 
9  "  11 
TABLE  NO.  4. — NUMBER  OF  DROPS  OF  DISTILLED  WATER  THAT  WERE 
REQUIRED  TO  WEIGH  I  GRAMME,  DROPPED  IN  SECONDS,  FROM  THE 
DIFFERENT  DROPPING  DEVICES  INDICATED. 
T.  K.  dropping  bottle,  flat  stopper  13  to  16 
............  13  "  15 
"           "      heart-shape  stopper  14  "20 
American  dropping  bottle  9  "12 
German          "          "   9  "11 
"              "         "      thin  lips                                    10  "15 
Sallerones  dropping  flask  .....      .                                15  "18 
Proposed  standard  dropper  (outlet  3  mm.)  .10  "26 
Decigramme  dropper                                                          9*5  "  11 
Same  principle  applied  to  a  dropping  funnel  10  • 
.  It  will  be  apparent  to  every  one  that  these  figures  are  at  variance 
with  the  results  of  investigators  as  usually  published.    They  can 
