Am.  Tour.  Pharni.  ) 
February,  1921.  J 
Current  Literature. 
creased  the  vitamin  content  40.6  per  cent.  In  this  case  the  beans 
were  somewhat  overcooked.  Cooking  navy  beans  in  0.5  per  cent, 
sodium  bicarbonate  solution  for  1  hour  and  10  minutes  caused  a 
loss  of  37.5  per  cent,  of  the  vitamin.  A  large  proportion  of  the 
vitamin,  from  36  to  70  per  cent.,  was  present  in  the  cooking  water. 
(From  Jour.  Biological  Chemistry,  Baltimore,  through  Jour.  Amer. 
Med.  Assoc.,  Nov.  13,  1920.) 
New  Method  of  Estimating  Quinine. —  (C.  Bamberger — 
Pharni.  Zcntralb.,  1920,  61,  257-259;  through  Chem.  Zeit.,  1920, 
44,  Rep.  223.)- — Two  and  a  half  grms.  of  cinchona  bark  are  heated 
for  ten  minutes  over  the  water-bath  with  two  c.  c.  of  hydrochloric 
acid  and  20  c.  c.  of  water,  and  the  mixture  then  cooled,  shaken 
with  25  grms.  of  chloroform  and  50  grms.  of  ether,  and  treated 
with  5  grms.  of  sodium  hydroxide  solution.  The  contents  of  the 
flask  are  vigorously  shaken  (about  300  times)  within  two  to  three 
minutes,  and  treated  with  sufficient  plaster  of  Paris  (about  40  to 
50  grms.)  to  clarify  the  liquid,  and  60  grms.  of  the  clear  chloroform- 
ether  layer  transferred  to  a  separating  funnel.    It  is  shaken  twice 
N 
(for  two  minutes  each  time)  with  s  c.  c.  of  —  hvdrochloric  acid 
\  10  3 
and  twice  with  10  c.  c.  of  water,  and  the  extracts  united  and  titrated 
N 
with  — -  potassium  hydroxide  solution,  methyl  red  being  used  as 
indicator.  The  results  agree  closely  with  those  obtained  with  the 
Swiss  Pharmacopoeia  method,  and  the  methods  of  Frerichs  and 
Mannheim.    (From  The  Analyst,  November,  1920.) 
Determination  of  the  Jellying  Power  of  Gelatins  and 
Glues  by  tfie  Polari meter. — C.  R.  Smith  (/.  Ind.  and  Eng. 
Chem.,  1920,  12,  879). — The  optical  rotation  of  solutions  of  all 
gelatins  and  glues  at  35 0  C.  is  practically  constant,  ranging  from — 
6.70  to  7.200  Yentzke  per  grm.  of  solid  material,  but  on  cooling  to 
15 0  C.  the  rotation  increases  proportionately  to  the  viscosity  of 
the  solution.  Increase  in  concentration  gives  higher  values,  but  by 
keeping  the  solutions  for  several  hours  at  150  C.  a  gradual  de- 
crease is  observed,  so  that  solutions  of  all  strengths  under  the 
above  working  conditions  yield  a  constant  rotational  value  for  any 
