338 
Paraffin  as  an  Excipient. 
Am.  Jour.  Pharm. 
July,  1886. 
(a)  30  c.c  required  2V8  c.c.  oxalic  sol.  to  complete  decolorization. 
(6)  50  c.c      "       36-25  c.c. 
(c)  50  c.c.      "    ;   36-3  c.c. 
130  c.c.      u      94-35  c.c. 
130X3-096 
Then  10Q0 —  ='40248  gm.  (K2Mn208)    calculated,  and  94'35  X 
•00332  =-313242  gm.  (K2Mn208)  found,  equivalent  to  77'82  per 
cent. 
This  pill-mass  Avas  only  kept  about  half  the  time  the  former  had 
been,  but  the  results  (while  not  strictly  comparable)  show  that  if  the 
pills  are  freshly  dispensed  with  a  minimum  quantity  of  excipient,  and 
not  coated  with  a  reducing  medium,  Martindale's  mixture  practically 
answers  its  purpose. 
Estimation  of  unreduced  salt  in  a  pill-mass  containing  chloride  of 
gold  and  sodium  {sodium  chlor-aurate). — The  gold  salts  employed  were 
obtained  from  a  firm  well  known  as  manufacturers  of  fine  and  rare 
chemicals,  but  it  was  considered  desirable  for  the  purpose  of  the  fol- 
lowing investigations  to  ascertain  beforehand  the  exact  percentages  of 
metal  and  chlorine  contained  in  each.  For  this  purpose  a  small  quan- 
tity of  the  contents  of  the  15  grain  tubes  was  weighed  off  for  the  es- 
timation of  gold  and  chlorine,  whilst  the  remainders  were  also  weighed 
off  at  the  same  time  (to  avoid  deliquescence),  and  worked  up  into 
pill-masses.  All  the  gold  estimations  were  made  by  reduction  with 
oxalic  acid  in  slight  excess,  whilst  the  chlorine  in  the  filtrate  from  the 
precipitated  metal  was  estimated  gravimetrically  by  precipitation  with 
AgN03  in  presence  of  a  large  excess  of  HN03  in  order  to  prevent  any 
argentic  oxalate  from  precipitating  with  the  chloride.  It  was  noticed 
in  shaking  out  the  salt  ( Na AuCl4.2H20)  that  the  crystals  seemed 
moist,  and  the  somewhat  low  percentages  found  may  perhaps  be  ac- 
counted for  by  this  fact.  '420  gm.  of  sodium  chlor-aurate  was  taken. 
This  gave  *200  gold  and  *13892  chlorine.  The  following  are  the  per- 
centages found  with  those  calculated  for  !NaAuCl4.2H20  : — 1 
Calculated.  Found. 
Na=  5-8 
Au  =49*47  ..47-619 
Cl4  =  35-67  33-076 
2(H20)=  9-06 
 100-00  
1  Au  =  196-2,  Ag  =  107-66,  Na  =  22"995,  0  =  15-96,  N==  14'01,  a =35-37,  H  =  1. 
1  Die  Atomgewichte  der  Elemente.'    (Meyer  and  Seubert.) 
