184 
Dispensing  by  Drops. 
Am.  Jour.  Pharm. 
April,  1884. 
drop  can  be  obtained  twice  as  large  as  another  where  the  cork  has 
been  held  at  a  different  angle,  the  same  is  true  with  a  bottle,  but  not 
quite  in  so  great  a  degree. 
The  fulness  of  the  bottle  also  exerts  some  influence,  as  tincture  of 
aconite,  when  dropped  from  an  ounce  vial  full,  yielded  110  drops  to 
the  drachm,  but  when  only  one-fourth  full  gave  116  drops,  also  liquor 
potassii  arsenitis,  from  a  full  ounce  vial,  gave  66  drops,  and  when  one- 
third  full,  only  57.  In  the  one  case,  decrease  in  the  amount  of  liquid 
decreased  the  size,  while  in  the  other  it  was  increased.  The  drop  from 
an  ounce  vial  was  in  most  instances  the  same  as  from  the  shop  bottle. 
By  a  careful  perusal  of  the  above  we  can  readily  notice  that  the 
different  classes  of  preparations  can  be  grouped  together,  as  for  instance, 
the  tinctures  or  alcoholic  preparations  may  be  classed  as  a  group,  whose 
drops  are  about  one  half  the  size  of  the  aqueous  liquids,  while  the  oils 
and  acids  form  an  intermediate  group  between  the  two.  Durand  must 
have  taken  notice  of  this  fact,  when  he  laid  down  his  two  general  rules 
concerning  drops  as  follows : 
First :  that  liquids,  with  a  small  proportion  of  water,  afford  a  small 
drop,  and  vice  versa. 
Second  :  that  amongst  liquids  containing  a  large  proportion  of  water, 
those  not  charged  with  remedial  substances,  give  a  larger  drop  than 
those  same  liquids  having  extraneous  bodies  in  solution. 
In  summing  up  my  labors  on  this  subject,  there  is  only  one  general 
conclusion  that  I  will  mention,  as  it  covers  all  of  the  others,  and  if 
properly  heeded  may  be  the  means  of  saving  considerable  trouble,  and 
I  might  say  is  also  in  harmony  with  those  who  before  me  have  given 
the  subject  a  still  more  thorough  investigation.  Having  shown  that 
the  same  liquid  under  different  and  even  the  same  circumstances,  varies 
in  dropping  so  much,  that  no  reliance  whatever  can  be  placed  in  this 
method  of  dispensing  medicines,  therefore  their  administration  in  this 
form  is  always  attended  with  more  or  less  danger. 
Iodine,  Salicylic  Acid  and  Sodium  Salicylate,  according  to 
Dr.  Ritten,  when  applied  to  the  skin  either  as  simple  solution,  or  as 
spray  or  in  the  form  of  ointment  are  not  absorbed  until  after  the 
normal  skin  has  been  altered  by  these  irritants. — Arch.  f.  Klin.  Med. 
xxxiv,  p.  143. 
