436 
Fucus  Vesiculosus. 
Am.  Jour.  Pharm, 
Sept , 1880. 
wine,  dried  at  ioo°C.  and  weighed.     Weight  found  to  be  -390  gram. 
This  gave  '061  gram  potassium,  and  the  sodium  '037  gram. 
The  hydrchloric  solution  was  made  up  to  30*  cc. 
Estimation  of  Phosphoric  Acid. — To  10  cc.  of  solution  a  solution  of 
acetic  acid  and  a  solution  of  acetate  of  sesquioxide  of  iron  was  added, 
producing  a  white  precipitate  of  ferric  phosphate.  When  dried  at  a 
very  low  heat  it  weighed  '191  gram,  thus  showing  -120  gram  phos- 
phoric acid. 
Estimation  of  Sulphuric  Acid. — To  10  cc.  of  the  solution  barium 
chloride  was  added  until  no  further  precipitate  was  noticeable.  The 
precipitate  was  allowed  to  settle,  and  the  liquid  decanted  from  it ;  it 
was  then  further  washed  by  decantation,  filtered,  dried,  and  weighed 
•080  gram,  which  indicates  '032  gram  sulphuric  acid. 
Estimation  of  Calcium.  — 10  cc.  of  solution  was  evaporated  nearly  to 
dryness  and  treated  with  strong  alcohol  until  the  product  dissolved.  A 
slight  excess  of  concentrated  sulphuric  acid  was  added,  and  the  solu- 
tion allowed  to  stand  two  hours.  The  precipitate  was  then  transferred 
to  a  weighed  filter,  and  washed  with  strong  alcohol  until  the  filtrate 
gave  no  acid  reaction  to  test  paper.  After  the  removal  of  all  the  free 
acid  the  washing  was  continued  with  40  per  cent,  alcohol  until  the 
filtrate  left  no  residue  on  evaporation.  The  precipitate  was  then  dried 
and  weighed,  and  the  process  repeated  until  the  last  two  weighings 
were  the  same,  '145,  which  shows  '042  calcium. 
Estimation  of  Magnesia.  — 10  cc.  of  the  solution  was  taken.  The 
calcium  was  removed  as  oxalate.     The  solution  was  evaporated  to 
about  one-fourth  and  an  excess  of  pure  dilute  sulphuric  acid  added  ; 
this  was  evaporated  to  dryness  in  a  weighed  porcelain  dish,  at  a  very 
low  heat.    The  heat  was  gradually  applied.     The  flame  was  made  to 
play  on  the  cover  from  above  until  there  was  no  excess  of  acid,  then 
agitated  over  a  lamp;  when  cooled  it  weighed  '142  sulphate  of  mag- 
.     MsSo,  .  • 
nesia,  ^  -  indicating  '025  magnesia. 
1 20  ' 
Summary . — 
[     VVAter,  .  .  .  .  .  2'2^ 
A  Ash,  .  .  .  .  .  1-59 
i     Organic  matter,  .  .  .  .     6*15  =  lo' 
f     Potassium  chloride,  .  .  .  .  -348 
I      Sodium  iodide,  .  .  .•  .  •252 
■g       f      Sodium  bromide,  .  .  .  .  '324 
]      Magnesium  phosphate,  .  .  .  -312 
I      Calcium  phosphate,  .  ,  .  .  '225 
y     Calcium  sulphate,  ....  '138  ^  i"599' 
