154     ON  THE  UNCERTAINTY  OF  PHARMACEUTICAL  PREPARATIONS. 
many  degrees  of  the  burette  are  required  to  complete  the  saturation 
of  the  lime.  If  35  are  required  for  this  purpose,  100-35,  or  65, 
represents  the  proportion  of  lime  absorbed  by  the  charcoal ;  this  is 
the  number  representing  its  standard.  By  operating  with  a  burette 
graduated  from  the  bottom,  the  degree  of  the  charcoal  experimented 
on  may  be  read  directly. 
The  author  adds,  that  if  these  numbers  be  depended  upon  for 
the  calculation  of  the  absolute  lime-absorbing  power  of  the  char- 
coal, they  will  lead  to  error,  as  it  appears  that  this  substance  ab- 
sorbs a  large  quantity  of  lime  in  proportion  as  the  quantity  in  the  so- 
lution is  larger.  An  equilibrium  is  set  up  between  the  action  of 
the  charcoal,  the  dissolving  force  of  the  water,  and  the  capacity  of 
the  saturation  of  the  sugar,  which  varies  according  to  the  quantity 
of  these  elements  in  the  solution.— Chem.  Gaz.Jan.  1, 1854,  from 
Comptes  Rendus,  Oct.  17,  1853,  p.  610. 
ON  THE  UNCERTAINTY  OF  THE  COMPOSITION  OF  PHARMACEU- 
TICAL PREPARATIONS.  AND  THE  MOST  ELIGIBLE  FORM  OF 
MEDICINES  FOR  ADMINISTRATION. 
By  W.  B.  Chapman.  j\f.  D.,  of  Cincinnati. 
The  uncertainty  of  the  purity  and  strength  of  remedial  agents  is 
a  serious  inconvenience  to  the  practitioner  of  medicine,  and  one 
over  which  he  has  but  little  control,  as  he  must  depend  mainly 
upon  the  druggist  from  whom  he  purchases  his  stock  ;  and,  although 
we  have  laws  which  require  the  inspection  of  drugs  and  chemicals 
that  are  imported  into  the  United  States,  and  which  doubtless  have 
operated  beneficially  in  keeping  from  our  markets  large  quantities 
of  inferior  articles,  still  much  watchfulness  is  requisite  to  prevent 
sophistication  at  home  by  unprincipled  dealers,  whose  only  object 
is  "  to  buy,  sell,  and  get  money  ;  get  it  honestly  if  they  can,  if  not, 
1  get  it." 
This  is  a  subject  of  vast,  importance,  and  one  which  should  en- 
gage more  of  the  attention  of  the  practitioner  than  it  usually  does, 
for  how  is  it  possible  for  him  to  do  justice  to  his  patient  or  himself 
whilst  there  is  so  much  uncertainty  in  the  quality  of  the  agents  he 
may  wish  to  employ  1 
How  are  we  to  ascertain  the  purity  of  our  articles  1    Most  per- 
