Am7u°i^'wo5frm*}      Notes  on  Pharmaceutical  Subjects.  327 
know  what  they  are  and  how  to  prepare  them.  A  description  of 
such  simple  apparatus  as  is  needed  will  perhaps  be  the  best  and 
easiest  way  to  make  the  subject  plain  to  those  who  fail  at  first  to 
understand  the  matter. 
Thus  a  i-per  cent,  solution  of  cocaine  hydrochlorate  is  readily 
made  by  mixing  10  grains  of  the  salt  with  a  small  quantity  of  dis- 
tilled water  and  pouring  it  into  a  vial  previously  counterpoised  on  a 
scale,  and  then  adding  distilled  water  until  it  balances  1,000-grain 
weight.  To  save  trouble  in  making  subsequent  lots,  a  mark  may 
be  made  on  the  vessel,  and  the  salt  weighed  mixed  as  before  with  a 
small  quantity  of  distilled  water,  and  the  required  quantity  of  dis- 
tilled water  added  to  make  the  measure  of  1,000  grains. 
It  has  been  found  very  convenient  and  a  great  saving  of  time  to 
keep  a  solution  of  strychnine  sulphate,  which  is  often  prescribed,  in 
mixtures  of  such  strength  that  2  fluid  drachms  will  contain  I  grain 
of  the  salt,  so  that  by  using  1  fluid  drachm  of  the  solution  when 
y2  grain  of  the  salt  is  prescribed  much  time  is  saved  and  the  thor- 
ough mixture  of  the  salt  is  secured. 
A  mixture  of  arsenious  acid  and  sugar  of  milk  is  also  found  to  be 
useful,  I  grain  of  the  acid  being  triturated  with  1 5  grains  of  dry  granu- 
lated sugar  of  milk  until  an  impalpable  powder  is  obtained ;  if 
y2  grain  of  the  acid  is  prescribed,  8  grains  of  the  mixture  will  be 
required. 
Triturates  of  arsenious  acid,  strychnia,  corrosive  sublimate,  calo- 
mel, morphine  and  several  other  active  remedies  are  found  very  use- 
ful, and  render  dispensing  them  safer  and  much  easier. 
Phosphorus  is  sometimes  prescribed  in  pilular  form,  and  many 
dispensers  have  found  it  quite  troublesome  to  make  such  pills  and 
to  be  certain  that  the  exact  quantity  is  in  every  pill.  A  method 
that  has  proven  satisfactory  is  to  weigh  a  given  quantity  of  the 
phosphorus,  place  it  in  a  test-tube  and  add  sufficient  pure  carbon 
bisulphide  to  dissolve  it ;  then  butter  of  cocoa  is  added  in  small 
portions  until  fifteen  times  its  weight  has  been  added.  The  test-tube 
should  be  first  fitted  with  a  cork  and  the  mixture  shaken  after  each 
addition  of  the  cOcoa  butter,  and  when  all  has  been  added  the  test- 
tube  should  be  placed  in  warm  water  and  shaken  until  thoroughly 
mixed.  Of  course,  each  16  grains  of  this  mixture  will  contain  I 
grain  of  phosphorus,  and  in  this  way  the  phosphorus  can  be  easily 
made  into  pills  with  the  other  articles  directed  in  the  prescription. 
