AnASustS!m"}    Abstracts  of  Theses  on  Chemical  Subjects,  365 
bright  color  be  desired,  the  saffron  may  previously  be  moistened  and 
triturated  with  a  little  water  or  alcohol,  or  the  fresh  and  faintly 
damp  mixture  may  be  subjected  to  considerable  pressure  in  the 
triturating  process."  I  am  unable  to  find  such  a  note  in  the  British 
Pharmacopoeia,  and  the  formula  there  given  does  not  contain  any 
saffron,  and  the  proportion  of  the  other  ingredients  varies  somewhat 
from  that  given  in  the  Formulary. 
The  note  added  to  Syrupus  Papaveris  states :  "  The  product  is 
practically  identical  with  the  Syrupus  Papaveris  of  the  B.P."  I  am 
unable  to  find  this  as  an  official  preparation  in  the  British  Pharma- 
copoeia. The  only  syrup  of  poppies  in  the  British  Pharmacopoeia 
is  the  Syrupus  Rhcedos  made  from  the  red  poppy  petals,  an  entirely 
different  drug. 
ABSTRACTS  OF  THESES  ON  CHEMICAL  SUBJECTS.1 
By  J.  W.  Ehman. 
Magnesii  Carbonas. — By  C.  M.  McClure.  An  investigation  of  the 
relation  between  impurities  in  magnesium  carbonate  and  the  diffi- 
culty in  filtering  and  keeping  stock  solution  of  magnesium  citrate. 
The  following  table  gives,  in  part,  the  results  of  chemical  analysis 
of  six  samples  of  magnesium  carbonate  : 
U.S.P. 
Require- 
ments. 
I 
II 
III 
IV 
V 
VI 
Per  cent.  MgO  by  residue  on 
40 
42-66 
41*45 
43"io 
42-28 
43-00 
42  66 
Per  cent.  MgO  by  direct  titration, 
42-32 
41-12 
42-89 
4121 
40-79 
40-00 
Per  cent.  MgO  in  residue  from 
96 
95  "93 
96-41 
95-22 
94-48 
93'43 
92*75 
•063 
•0076 
none 
•023 
•01 63 
136 
■0096 
•236 
•023 
.  -183 
•129 
Per  cent.  Al  and  Fe  calculated  as 
none 
•105 
•116 
none 
'430 
•158 
•209 
Experiments  were  made  with  each  sample  by  dissolving  15  grammes  in  a  solution  of  33 
grammes  citric  acid  in  120  c.c.  of  water,  filtering  and  allowing  to  stand  : 
IV  showed  no  precipitate. 
II  showed  a  very  slight  precipitate  in  ten  days. 
I  and  III  showed  a  slight  precipitate  in  seven  days. 
VI  showed  a  distinct  precipitate  in  seven  days. 
V  showed  a  distinct  precipitate  in  four  days. 
In  ten  days  the  precipitates  in  I,  III,  V  and  VI  had  increased  in  amount. 
1  The  experimental  work  embodied  in  these  theses  was  performed  in  the 
chemical  laboratory  of  the  Philadelphia  College  of  Pharmacy. 
