694 
Current  Liter  attire. 
f  Am.  Jour.  Pharm. 
*     October,  19 19. 
that  with  acid  of  this  strength  the  nucleins  are  not  further  hydro- 
lyzed,  as  was  suggested  by  some  workers.  H.  F.  E.  H.  (The  An- 
alyst, May,  19 19). 
Iodimetric  Estimation  of  Acetone. — W.  Marriott  (/.  Biol. 
Chem.,  1918,  16,  281 ;  through  /.  Pharm.  Chim.,  1919,  19,  133-136). 
: — With  reference  to  the  method  described  by  Shaffer  and  Marriot 
{Analyst,  1914,  39,  184)  for  the  estimation  of  acetone  and  B-hydrox- 
ybutyric  acid  in  urine,  in  which  use  is  made  of  Messinger's  method 
for  the  estimation  of  acetone,  the  following  work  was  done  to  con- 
trol the  accuracy  of  that  method :  A  sample  of  acetone  regenerated 
from  the  bisulphite  compound  was  purified  by  distillation  with  per- 
manganate and  then  with  calcium  chloride.  The  product  was  then 
submitted  to  fractional  distillation,  and  the  fraction  distilling  at  560 
to  750  C.  collected.  Very  considerable  care  is  required  in  making 
up  and  manipulating  dilute  aqueous  solutions  of  acetone.  The 
sample  is  weighed  out  in  a  small  glass  bulb  of  2  to  3  Cc.  capacity. 
The  bulb  is  dropped  into  a  2-liter  measuring  flask  and  broken  under 
water,  the  solution  being  then  made  up  to  the  mark.  Precautions 
are  required  to  prevent  loss  of  acetone  in  measuring  off  this  dilute 
solution  for  analysis.  The  flask  is  closed  by  a  rubber  stopper  with 
two  holes,  through  one  of  which  is  passed  a  25  Cc.  pipette.  The 
pipette  is  filled  by  means  of  a  rubber  ball,  and  the  measured  liquid 
is  transferred  to  a  flask  containing  500  Cc.  of  water,  the  point  of 
the  pipette  being  dipped  below  the  surface  of  the  water.  To  this 
solution  50  Cc.  of  N/10  iodine  and  10  Cc.  of  caustic  soda  solution 
at  60  Gms.  per  100  Cc.  are  added.  The  flask  is  corked,  shaken,  and 
allowed  to  remain  for  five  to  ten  minutes;  15  Cc.  of  hydrochloric 
acid  are  added,  and  the  liberated  iodine  is  titrated  with  N/10  thio- 
sulphate.  Each  Cc.  of  N/10  iodine  consumed  is  equivalent  to 
0.000968  Gm.  of  acetone.  The  results  are  quite  sufficiently  accu- 
rate :  for  instance,  acetone  taken  30.62  Mgrms.,  found  30.64  Mgrms. ; 
taken  20.95,  found  21.09  Mgrms.  Geelmuyden  has  stated  that  small 
quantities  of  acetone  cannot  be  distilled  from  aqueous  liquids  with- 
out appreciable  loss ;  the  author  has  proved  that,  with  suitable  pre- 
cautions, acetone  can  be  distilled  and  collected  quantitatively  in  a 
few  minutes.  Five  hundred  Cc.  of  an  aqueous  solution  containing 
33.7  Mgrms.  of  acetone  determined  by  the  above  method  were 
placed  in  a  Kjeldhal  distillation  flask  of  800  Cc.  capacity,  with  a  tin 
