470  British  Pharmaceutical  Conference.  {^jSerS' 
One  miuute  is  equivalent  to  "03  gramme  strophanthin  per  100  c.c.  of  the 
liquid  examined. 
Example  : — 
100  c.c.  of  the  1885  tincture  were  treated  as  above  ;  the  rotation  equalled  + 
o°3o/.     '    '  0  °3  X  3°  _  q.j3  gramme  strophanthin  in  100  c.c.  tincture. 
It  is  necessary,  of  course,  to  divide  the  rotation  by  five,  as  the  liquid  is  five 
times  stronger  than  the  original  tincture. 
In  the  case  of  the  extract,  the  determination  must  be  made  before  the  reduc- 
tion with  milk  sugar. 
One  gramme  of  extract  is  dissolved  in  5  c.c.  warm  water.  2  c.c.  solution  of 
basic  acetate  of  lead  are  then  added,  the  mixture  heated  for  a  few  minutes  and 
filtered,  the  precipitate  is  washed  with  warm  water  until  the  filtrate  and  wash- 
ings measure  20  c.c.  The  rotation  is  then  observed,  and  the  amount  of  stroph- 
anthin calculated  therefrom  as  in  the  tincture. 
ALGINOID  IRON  AND  SOME  OTHER  ALGINOIDS. 
By  E.  C.  C.  Stanford. 
The  property  of  passing  through  the  stomach  unchanged  is  possessed  by  few 
if  any  medicines,  hence  where  this  is  desired,  it  is  usually  necessary  to  cover 
the  medicament  with  such  a  body  as  keratin,  on  which  the  stomach  has  no 
action.  A  complete  series  of  therapeutic  compounds  having  this  general  prop- 
erty would  be  new  to  medicine,  would  probably  give  rise  to  new  developments, 
and  add  considerably  to  the  physicians'  weapons  for  attacking  disease.  Such 
a  series  appear  to  be  presented  in  the  alginates.  As  far  as  has  been  ascertained, 
alginic  acid  and  its  insoluble  medicinal  salts,  iron,  zinc,  mercury,  bismuth,  lead, 
silver,  antimony,  arsenic,  etc.,  are  unacted  on  by  the  gastric  digestion,  and  pass 
the  stomach  unchanged.  Hence  the  action  of  these  metals  may  be  expected 
to  present  some  differences  or  variations  of  the  ordinary  effects  when  presented 
in  this  form,  and  for  a  distinctive  and  expressive  name  the  author  calls  these 
"Alginoids." 
The  chemical  formula  of  alginic  acid  is  represented  as  C7(5H80N2O22  {Jour. 
Soc.  Chem.  Ind.f  1886,  p.  218).  It  is  a  strong  acid  evolving  carbonic  acid  from 
the  alkaline  carbonates  in  the  cold  ;  however,  it  is  assimilated  and  it  is  known 
to  be  a  nutritious  food.  The  soluble  alginates  are  those  of  the  alkaline  metals 
and  of  magnesium.  The  insoluble  salts  are  of  the  other  alkaline  earths  and 
of  vthe  heavy  metals. 
Al,ginoid  Iron  or  Ferric  Alginate. — Ferrous  salts  are  not  precipitated  by 
sodium  alginate,  the  ferric  salt  is  obtained  by  decomposing  ferric  chloride  with 
sodium  alginate,  both  in  solution.  A  gelatinous  brown  precipitate  is  obtained. 
When  dry  it  forms  a  tasteless  insoluble  brown  powder,  having  a  composition 
leading  to  the  formula  C76N77Fe3N2022.    It  contains  10*97  per  cent,  of  Fe. 
It  is  soluble  in  ammonia,  forming  a  deep  reddish-brown  solution,  which,  on 
evaporation,  becomes  insoluble  in  water,  so  that  the  alginoid  iron  can  be 
administered  in  a  liquid  form. 
The  dry  powder  has,  however,  been  mostly  administered,  and  in  all  cases  of 
anaemia  and  chlorosis,  even  where  gastric  ulceration  was  present,  it  has  been 
well  borne,  and  showed  a  sedative  action  by  arresting  vomiting  and  sickness. 
