Am.  Jour.  Pharm.  j.  AcetOUC  ill  the  Body.  $7 
January,  1921.    I  - 
has  trenchantly  remarked  that  fat  at  one  time  may  save  the  life 
of  the  diabetic,  but  at  another  may  destroy  it. 
Widmark  2  has  recently  demonstrated  at  the  physiologic  institute 
in  Lund,  Sweden,  that  free  acetone  belongs  to  the  group  of  sub- 
stances that  can  with  the  greatest  ease  penetrate  living  cells.  Hence 
they  diffuse  readily  throughout  the  organism  and  tend  to  avoid  undue 
concentration  at  any  locality  or  in  any  special  tissue.  Acetone  itself 
passes  into  the  urine  by  the  process  of  diffusion;  hence  the  con- 
centration of  this  compound  in  the  blood  and  urine  is  usually  the 
same.  Aceto-acetic  acid  (diacetic  acid),  to  which  the  well-known 
ferric  chloride  urinary  test  of  Gerhard  is  attributable,  depends  on 
the  characteristic  secretory  functions  of  the  kidneys  for  its  elimina- 
tion; consequently  its  concentration  is  commonly  higher  in  the 
urine  than  in  the  blood. 
It  also  appears  from  the  observations  of  Widmark  3  that  the 
elimination  of  acetone  through  the  lungs  is  a  pure  diffusion  process. 
From  his  data  there  is  no  reason  to  suppose  that  any  secretion  of  the 
volatile  compound  takes  place,  such  as  has  at  times  been  assumed 
for  the  passage  of  certain  gases  through  the  alveolar  membranes. 
From  a  simple  determination  of  the  concentration  of  acetone  in  the 
alveolar  air,  so  commonly  collected  nowadays  in  the  estimation  of 
carbon  dioxide  factors,  it  is  possible  to  secure  an  accurate  calculation 
of  the  free  acetone  concentration  of  the  blood.  Widmark  points 
out  that  accordingly  in  a  diabetic,  by  combined  blood  estimation 
and  analysis  of  alveolar  air,  one  may  arrive  at  an  understanding 
of  the  relationship  between  the  free  acetone  and  the  total  acetone 
in  the  blood.  The  method,  he  adds,  has  this  great  advantage,  that 
the  relationship  between  the  acetone  and  the  aceto-acetic  acid  can 
in  no  way  be  disturbed  by  the  analysis ;  the  separation  of  the  free 
acetone  from  the  aceto-acetic  acid  is  effected,  so  to  speak,  with  the 
organism  itself  as  distillation  apparatus.  The  ability  to  differentiate 
and  estimate  the  various  ketone  substances  with  accuracy,  as  is  al- 
ready accomplished  for  the  sugar  in  the  blood  and  urine  of  glycosuric 
patients,  is  likely  to  prove  helpful  in  the  clinic  of  diabetes. 
2  Widmark,  E.  M.  P. :  "Studies  in  the  Acetone  Concentration  in  Blood, 
Urine  and  Alveolar  Air.  II.  The  Passage  of  Acetone  and  Aceto-Acetic  Acid 
into  the  Urine,"  Biochem,  J.,  14:  364  (July)  1920. 
3  Widmark,  Ej  M.  P.  Ibid,  p.  379. 
