Am.  Jour.  Pharru.  > 
August,  1902.  X 
Drops  as  Dose  Measures. 
383 
tions  of  arsenic  and  its  salts,  solution  of  potassium  iodide,  tincture 
of  digitalis,  or  tincture  of  nux  vomica. 
With  several  of  these  preparations  the  initial  dose  is  of  compara- 
tively little  importance,  the  object  that  is  usually  sought  being  to 
find  out  the  amount  that  will  be  readily  tolerated  by  the  patient. 
For  this  purpose  the  dose  is  gradually  increased  until  marked  evi- 
dences of  physiological  action  manifest  themselves,  then  the  dose  is 
either  decreased  slightly  and  continued,  or  in  some  cases  decreased 
again  gradually  to  the  starting  point.  The  advantages  possessed 
by  drops  as  dose  measures  in  practices  of  this  kind  are  quite  appar- 
ent, especially  it  we  consider  that  the  actual  dropping  would  prob- 
ably be  done  by  the  same  person  and  in  the  same  way,  so  that 
there  would  be  little  or  no  probability  of  any  serious  error  or  differ- 
ences in  the  quantities  measured  out. 
This  practical  use  or  application  of  drops  would  also  appear  to 
offer  another  reason  for  adopting,  as  the  popular  idea  of  a  drop,  the 
maximum  quantity  that  may  be  obtained  by  any  of  the  usual 
methods  of  dropping. 
There  are  two  points,  or  lessons,  to  be  derived  from  this  com- 
parative study  of  drops  that  the  writer  would  like  to  call  particular 
attention  to. 
The  first,  of  course,  is,  that  the  dropping  of  approximate  quantities, 
where  weights  or  measures  are  directed,  is  a  habit  that  is  reprehen- 
sible, and  should  not  be  countenanced  or  practiced  under  any  con- 
ditions. For  use  at  the  dispensing  counter  a  graduated  pipette,  as 
suggested  by  the  late  Dr.  Squibb,  is  the  most  reliable  instrument 
for  measuring  out  small  quantities  of  a  liquid. 
The  second  point  is,  that  it  would  appear  impracticable  at  the 
present  time  to  adopt  a  fixed  standard  for  a  drop  or  dropper ; 
unless,  of  course,  we  were  able  to  compel  every  one  to  use  an  accu- 
rately made  and  somewhat  complicated  dropping  device.  Other- 
wise the  factors  that  enter  into  and  govern  the  size  of  the  drop  are 
too  numerous  to  be  brought  under  control  in  the  present  state  of 
our  knowledge. 
BIBLIOGRAPHY. 
Among  those  which  will  be  found  to  contain  interesting  information 
for  any  one  who  wishes  to  pursue  this  subject  further,  the  writer  would 
like  to  call  particular  attention  to  contributions  by  the  following : 
