AMsiptTOM37SM'}  Unguentum  Beazoini.  391 
reweigh  ;  the  difference  is  the  amount  of  lactic  acid  poured  out. 
Without  some  such  precaution,  the  small  drop  of  acid  adhering  to 
the  rim,  after  pouring  out,  would  rapidly  abstract  enough  moisture 
from  the  air  to  make  it  troublesome  to  follow  the  increase  with  a  deli- 
cate balance. 
The  results  of  the  assay  show  that  nearly  all  the  samples  come  up 
to  the  standard  fixed  by  the  U.  S.  Pharmacopoeia.  Only  the  last 
two  samples  are  short,  but  in  view  of  the  good  reputation  which  Mar- 
quart's  preparations  generally  bear,  I  am  inclined  to  believe  that  this 
is  owing  to  the  date  of  the  acid,  which  was  made  at  a  time  when  there 
was  much  less  demand  for  it.  I  did  not  succeed  in  obtaining  any  of 
his  recent  acid. 
The  following  table,  containing  the  results  of  the  assay,  explains 
itself: 
Grammes. 
Neutralize 
NaO. 
Correspond- 
ing to 
C6  H6  Oe. 
90  pts.  neutra- 
lize of 
KO,HO,2C02. 
Percent- 
age of 
C6  H6  Oe. 
"  (1873)  
Trommsdorf  (1873)... 
Gene  &  Co.  (1873)  , 
"  (1871)  
4-  6201 
5-  2629 
6-  1233 
4-4424 
3-5920 
2-4907 
1-1767 
1-3646 
1-6119 
1-1616 
0-8429 
0-6013 
3-4162 
3-  9617 
4-  6797 
3-3724 
2-4471 
1-7457 
74-  01  pts. 
75-  31  " 
76-  49  " 
75-99  " 
68-19  " 
70-16  " 
73-93 
75-  23 
76-  41 
75-91 
68-12 
70-09 
New  York,  August  15,  1873. 
UNGUENTUM  BENZOINI. 
(U.  S.  Ph.  1870.) 
By  H.  M.  Wilder. 
In  Medical  News  and  Library,  August,  1873,  p.  129,  the  Editor 
complains  of  the  above  ointment  as  made  according  to  the  U.  S. 
Pharmacopoeia  of  1870,  and  cautions  against  its  use  as  being  too 
irritant.    He  advocates  a  return  to  the  old  method,  by  digesting  the 
lard  with  benzoin  and  straining,  as  giving  an  entirely  bland  oint- 
ment. 
Permit  me  to  suggest  a  slight  modification  of  the  officinal  process, 
which  I  have  used  ever  since  I  began  to  make  it  with  the  tincture. 
It  happened  to  me,  as  to  everybody,  that  the  resin  separated  as  soon 
