Infusum  Digitalis, 
j  Am.  Jour.  Pharm. 
(       Sept.,  1878. 
contains  all  the  advice  that  can  be  given  on  paper,  being  one  of  the 
best  substitutes  for  personal  (oral)  instruction. 
Being,  as  before  stated,  only  a  beginner,  it  would  be  ridiculous  to 
recommend  a  particular  make  ;  but  thas  is  not  necessary  ;  for  the  pur- 
poses of  the  pharmacist  the  microscope  of  any  respectable  optician  is  the 
best.  The  differences  between  the  various  makes  are  only  perceptible 
when  employing  high  amplifications,  say  800  to  1,000  and  more  dia- 
meters. I  only  take  the  liberty  to  remark  that  we  here  in  Philadelphia 
have  Zentmayer,  147  South  Fourth  street ;  Queen,  924  Chestnut 
street,  and  the  branch  of  R.  &  J.  Beck  (London),  921  Chestnut  street 
— of  course  nearly  every  seller  of  optical  instruments  keeps  micro- 
scopes. 
Those  wishing  for  further  guidance  are  referred  to  the  synopsis  of 
American  microscopes,  by  R.  H.  Ward,  in  the  "American  Naturalist," 
vol.  vi,  1872,  p.  323  and  326. 
The  time  is  not  far  distant  when  a  microscope  will  belong  as  much 
to  the  necessary  outfit  of  a  well-appointed  drug  store  as  a  pair  of 
Troemner's  or  Becker's  prescription  scales. 
INFUSUM  DIGITALIS. 
By  Delbert  E.  Prall,  Ph.G. 
From  an  Inaugural  Essay. 
As  this  officinal  infusion  contains  two  fluidounces  of  tincture  of 
cinnamon  to  the  pint  it  will  keep  for  a  considerable  length  of  time 
without  decomposing,  the  tincture  of  cinnamon  containing  sufficient 
alcohol  to  preserve  it.  It  is,  therefore,  sometimes  kept  'on  hand  ready 
to  dispense.  But  soon  after  it  is  made  it  becomes  turbid,  and  an 
unsightly  precipitate  is  formed  which  usually  settles  at  the  bottom  of  the 
bottle,  and  the  question  arises  :  Would  it  be  proper  to  filter  and  dispense 
it  clear,  or  does  the  precipitate  contain  some  of  the  active  principles  of 
the  digitalis  ?  To  ascertain  whether  the  precipitate  contains  digitalin 
the  following  experiments  were  made  :  From  German  digitalis  leaves 
138  fluidounces  of  infusion  were  made  by  the  Pharmacopoeia  process. 
In  a  few  hours  it  became  turbid.  It  was  allowed  to  stand  two  months  ; 
at  the  end  of  this  time  some  of  the  precipitate  had  settled  to  the 
bottom  of  the  bottle  and  a  part  remained  suspended  in  the  liquid.  I 
then  began  to  filter  it  through  paper  pulp.    It  came  through  clear,  but 
