NOTES  ON  PRESCRIBING. 
345 
usually  six,  eight  or  twelve  doses,  and  that  these  last  are  now 
often  replaced  by  highly  concentrated  and  smaller  mixtures 
technically  called  droits,  each  bottle  of  which  contains  a  large 
number  of  doses.  Most  will  admit  that  the  dispensing  of  medi- 
cines in  the  form  of  draughts,  except  in  rare  cases,  involves  more 
labor  and  expense  than  are  necessary  for  any  purposes  of  accu- 
racy or  convenience.  But  in  resorting  to  the  compounds  which 
are  now  prescribed  as  drops,  we  are  going  to  the  other  extreme. 
It  is  a  practice  of  recent  introduction  and  finds  no  place  in  the 
Pharmacologia  of  Dr.  Paris,  who  does  not  give  a  single  specimen 
of  such  a  manner  of  prescribing. 
As  evidence  of  the  objectionable  character  of  prescribing 
medicine  in  a  very  concentrated  shape,  I  shall  quote  a  few  pre- 
scriptions, all  of  which  I  have  myself  lately  observed. 
R  Liquoris  strychnise  3ij. 
Tincturse  valerianse  siij. 
Spiritus  chloroformi  ^j. 
"      camphor 8e  sirj. 
Magnesise  sulphatis  ^j. 
Misturas  camphorse  ad  gviij. 
Misce.  Sumat  cochleare  unum  magnum  pro  dosi. 
This  mixture  is  too  alcoholic  to  retain  in  solution  the  sulphate 
of  magnesia,  which,  although  first  dissolved  in  the  camphor  julep, 
subsequently  concretes  into  a  crystalline  mass. 
R  Liquoris  Donovani  3viss. 
Potassse  bicarbonatis  ^v. 
Tincture  calumbse  ad  giij. 
Misce.  Signa — Forty  minims  (by  measure)  in  water 
twice  a  day  after  meals. 
Here  again  the  liquids  are  insufficient  to  dissolve  the  alkaline 
salt  which  remains  at  the  bottom  of  the  bottle  as  a  dense  white 
powder,  not  to  be  shaken  up  and  poured  into  a  minim  measure. 
R  Chlorodyne  giss. 
Sodae  biboratis  3j- 
Sp.  camphorse 
"   amnionic  com. 
"   setheris  sulph.  aa  3ss. 
