754 
Current  Literature. 
Am.  Jour.  Pharm. 
October,  1920. 
volume  such  that  an  aUquot  portion  of  25  Cc.  will  contain  between 
0.2  and  1.5  Mgm.  of  sulphur.  A  portion  of  25  Cc.  is  measured  out 
into  a  300  Cc.  wide-mouthed  conical  flask  and  acidified  with  one 
drop  of  dilute  hydrochloric  acid;  10  Cc.  of  a  solution  of  benzidine 
hydrochloride  (8  Gm.  per  litre)  are  added,  the  solution  is  shaken 
several  times  and  allowed  to  stand  for  fifteen  minutes  or  longer. 
The  benzidine  sulphate  is  collected  in  a  Gooch  crucible  on  an  asbestos 
pad  which  has  previously  been  treated  with  permanganate.  The 
flask  is  rinsed  three  times  with  5  Cc.  of  cold  water,  each  portion 
being  drained  through  the  filter  before  the  next  is  poured  on.  The 
asbestos  pad  and  precipitate  are  then  washed  back  into  the  original 
flask.  One  Cc.  of  10  per  cent,  sodium  hydroxide  is  added  and  the 
flask  is  warmed  on  the  steam  bath  to  dissolve  the  benzidine  sulphate. 
Water  is  then  added  to  bring  the  volume  up  to  about  100  Cc.  and  5 
Cc.  of  concentrated  sulphuric  acid  are  added.  The  flask  is  placed 
on  the  steam  bath  and  the  solution  is  titrated  hot  with  N/20  per- 
manganate until  the  red  color  fades  slowly.  An  excess  of  10  Cc. 
of  permanganate  is  added,  and  heating  on  the  steam-bath  continued 
for  exactly  ten  minutes.  Ten  Cc.  of  N/20  oxalic  acid  are  added, 
and  as  soon  as  the  solution  clears  the  titration  is  finished  off  with 
permanganate.  The  net  consumption  of  permanganate  is  multi- 
plied by  the  factor  0.041  to  obtain  the  number  of  Mgms.  of  sulphur 
in  the  portion  of  original  solution  taken,  this  factor  having  been 
ascertained  by  the  analysis  of  known  solutions  of  sulphates.  The 
results  are  essentially  the  same  as  those  obtained  by  the  gravimetric 
barium  sulphate  method.  By  using  the  entire  rinsings  of  the  bomb 
and  concentrating  to  25  Cc,  accurate  results  may  be  obtained  for 
oils  containing  only  o.i  per  cent,  of  sulphur. — J.  F.  B.  (From 
The  Analyst,  May,  ig2o.) 
Determination  of  ViTamine. — R.  J.  Williams  (/.  Biol.  Chem., 
42:  259-265,  1920). — The  author  has  previously  shown  that  the 
anti-beri-beri  vitamine  is  necessary  for  the  nutrition  of  yeast  (/. 
Biol.  Chem.,  38:  456,  1919),  and  this  fact  has  been  adapted  to  the 
estimation  of  the  amount  of  vitamine  present  in  solution.  The 
rate  of  growth  of  yeast  and  the  number  of  cells  produced  from  one 
cell  under  standard  conditions  in  eighteen  hours  is  directly  pro- 
portional to  the  amount  of  vitamine  present. 
The  microscopical  method,  although  yielding  good  results,  is 
troublesome,  and  the  following  gravimetric  method,  which  yields 
