ACTION  OF  OZONE  ON  ORGANIC  SUBSTANCES,  167 
the  odor  of  valeric  aldehyde.  If  at  this  moment  a  little  of  the 
liquid  is  supersaturated  by  an  acid,  the  odor  of  cyanic  acid 
will  be  perceived.  After  a  time  the  addition  of  an  acid  causes 
the  disengagement  of  carbonic  acid  only.  By  distilling  the  li- 
quid first  alone,  and  then  with  the  addition  of  phosphoric  acid, 
the  presence  of  butyric  acid  and  of  other  fatty  volatile  acids 
may  be  shown. 
Grrape  sugar  is  not  attacked  by  ozone,  but  in  presence  of 
soda,  potash,  or  carbonate  of  soda,  it  is  entirely  transformed 
into  carbonic  and  formic  acids. 
Cane  sugar  oxidizes  much  more  slowly  than  grape  sugar,  but 
the  same  products  are  formed. 
Glycerin  at  first  gives  a  faint  odor  of  acrolein.  The  liquid 
becomes  gradually  acid,  and  by  the  addition  of  another  small 
quantity  of  alkali  the  reaction  is  sustained,  and  carbonate,  for- 
miate,  and  propionate  of  potash  are  obtained. 
Olein  absorbs  ozone  in  presence  of  alkalies.  Glycerin  is  v 
first  attacked,  and  furnishes  acroleine  and  fatty  volatile  acids, 
while  oleic  and  palmitic  acids,  set  at  liberty,  combine  with  pot- 
ash, and  are  then  only  slowly  burnt.  The  reaction  is  the  same 
if  the  caustic  alkalies  are  replaced  by  carbonate  of  soda.  This 
reaction  is  of  some  importance,  as  possibly  explaining  the  de- 
composition of  fatty  matters  in  the  blood. 
Fatty  Volatile  Acids  (CH)n04. — The  only  acids  which  resist 
the  oxidizing  action  of  ozone  are  simply  burnt  slowly  and  con- 
tinuously in  the  presence  of  alkalies.  On  the  completion  of  the 
reaction,  only  formic  and  carbonic  acids  are  found  in  the  liquid. 
Solid  fatty  acids,  such  as  palmitic  and  stearic  acids,  are  at- 
tacked very  slowly,  even  in  presence  of  an  excess  of  alkali. 
Carbonic  acid  is  formed  immediately,  but  no  fatty  acid  contain- 
ing a  less  number  of  carbon  equivalents. 
Benzoic  and  succinic  acids  yield  only  carbonic   acid,  but 
they  are  burnt  much  more  rapidly  than  the  fatty  acids. 
Oxalic  acid  is  also  transformed  into  carbonic  acid,  but  very 
slowly. 
Citric  acid,  in  presence  of  an  alkaline  solution,  rapidly  takes 
up  ozone,  the  products  of  the  reaction  being  oxalic  and  car- 
bonic acids. 
Hippuric  acid  has  not  given  very  precise  results ;  carbonic 
