572 
Laboratory  Notes. 
f  Am.  Jour.  Pharm. 
\      Nov.,  1884. 
8  ounces  of  water,  filter  and  dissolve  in  the  filtrate  the  sugar.  The 
syrup  should  measure  1 6  fluidounces.  It  has  an  agreeable  flavor, 
makes  a  good  vehicle  for  administering  nauseous  medicines,  and  can 
be  made  to  take  the  place  of  syrup  of  tolu. 
Phosphoric  Acid. — Harry  Lovett  Miller,  Jr.,  examined  four  samples 
of  commercial  phosphoric  acid  and  found  these  to  respond  to  the  phar- 
macopoeial  tests  for  purity,  except  that  two  samples  contained  slight 
traces  of  phosphorous  acid,  and  one  sample  was  contaminated  with 
arsenic,  which,  estimated  as  Mg2As207  was  found  to  be  '031  per  cent. 
As203.  The  specific  gravities  ranged  between  1*229  and  1*347,  and  on 
evaporating  5  Gm.  of  the  acid  with  10  Gm.  PbO  and  igniting,  the 
residues  weighed  respectively  11*29,  11*57,  11*60  and  11*66  Gm.;  the 
Pharmacopoeia  requires  11*81  Gm. 
Magnesium  Carbonate. — Frank  Gibbs  Ryan  has  assayed  six  samples 
of  this  salt  prepared  by  different  manufacturers.  On  boiling  with  20 
times  their  weight  of  water,  filtering  aDd  evaporating,  residues  were 
left  weighing  *18,  *26,  *28,  *40,  *44  and  48  per  cent.  Magnesium  oxide 
was  estimated  merely  by  ignition,  carbon  dioxide  by  hydrochloric  acid 
in  a  Geissler's  apparatus,  and  water  by  the  difference.  The  results 
compared  with  the  theoretical  amounts  according  to  the  formula  recog- 
nized by  the  United  States  Pharmacopoeia  are  as  follows : 
U.  S.  P.  Samples      1         2         3  4  5  6 
MgO    41*32  41*85  44*65  43*25  43*45  41*00  41*30 
C02      36*36  34*90  34*05  33*75  32*45  31.85  31*80 
H20     22*32  23*25  21*30  23*00  24*10  27*15  26*90 
Granulated  Magnesium  Citrate. — James  A.  Pool  examined  three 
commercial  specimens,  and  determined  the  percentage  of 
Magnesium  carbonate,       3*9      1*0  3*2 
S03  4*3      1*0  0*7 
C02  12*5      7*5  105 
In  addition  to  these,  sodium,  potassium  and  citric  acid  was  found, 
and  neutral  solutions  of  each  specimen  on  being  boiled  with  silver 
nitrate,  yielded  a  metallic  mirror,  which  was  regarded  as  evidence  for 
the  presence  of  tartaric  acid. 
Blaud's  Pills. — John  A.  Murtaugh  obtains  a  satisfactory  pill  mass  by 
using  exsiccated  ferrous  sulphate,  and  well-dried  potassium  carbonate, 
forming  the  mass  with  powdered  liquorice  root  and  honey  (See  "Amer. 
Jour.  Phar.^  1883,  p,  141).  But  compression  is  preferred,  \  grain  of  acacia 
