"^'"mn^'ifst""'}  Relation  of  Acids  of  Nitrogen  to  Sulphuric  Acid,    1 49 
entirely  changed,  and  the  glycerides,  of  which  the  fat  had  originally 
consisted,  had  been  decomposed  so  as  to  leave  simply  a  mixture  of  the 
fatty  acids,  which  constituted  the  acid  portion  of  animal  fats.  The 
butter  had  in  fact  become  changed  into  a  substance  closely  resembling, 
in  character  and  composition,  the  substance  of  which  good  composite 
candles  are  made.  The  result  is  singular  as  showing  that  length  of 
time,  combined  with  exposure  to  moisture,  will  effect  the  decomposition 
which  the  manufacturer  of  stearin  has  to  effect  by  the  agency  of  heat 
and  acid.  The  other  and  older  sample  of  butter  had  been  taken  from 
an  alabaster  vase  in  an  Egyptian  tomb  ;  it  had  evidently  been  melted 
and  poured  into  the  vase,  and  carefully  sealed  over.  This  sample  was 
probably  about  2,500  years  old,  but  the  preservation  had  been  so  per- 
fect that  it  was  only  slightly  rancid  and  had  fully  retained  the  chemical 
properties  of  genuine  butter,  the  fat  not  having  been  decomposed  to  any 
sensible  extent.  This  sample  possessed  a  decided  taste  and  smell  of 
butter,  while  the  sample  from  the  bog  was  cheesy  rather  than  buttery 
in  smell. — Chem.  News^  Jan.  23,  1880. 
ON  THE  RELATIONS  OF  THE  ACIDS  OF  NITROGEN 
TO  SULPHURIC  ACID. 
By  G.  Lunge. 
Our  knowledge  of  this  relation  is  not  by  any  means  complete.  It  is 
well  known  that  nitrous  acid,  either  in  the  liquid  or  gaseous  form,  or 
produced  nascent  from  the  union  of  nitrogen  dioxide  with  oxygen,  is 
dissolved  by  sulphuric  acid  of  about  1*7  specific  gravity;  but  the 
behavior  of  nitrogen  tetroxide  toward  sulphuric  acid  is  not  accurately 
known.  The  author  has  shown  that  it  is  dissolved  by  sulphuric  acid, 
forming  nitrosulphuric  and  nitric  acids  ;  but  according  to  Weber  and 
Winkler,  nitrogen  tetroxide  is  dissolved  as  such  by  sulphuric  acid  of 
66°B.,  producing  a  reddish-yellow  solution,  which,  when  heated,  gives 
off  nitrogen  tetroxide  with  violent  ebullition,  and  leaves  a  liquid  having 
the  properties  of  nitrosulphuric  acid.  Winkler  stated  that  28*072 
grams  of  sulphuric  acid  at  6o°B.  absorbed  7*39.7  grams  of  nitrogen 
tetroxide,  but  that  on  heating  gently,  the  latter  was  entirely  expelled. 
Weber  describes  the  effects  of  nitrogen  tetroxide  on  sulphuric  acid  of 
■different  specific  gravities,  but  only  qualitatively  :  thus,  sulphuric  acid  at 
a  specific  gravity  of  1*7  absorbs  nitrogen  tetroxide  without  becoming 
•colored  ;  hence  it  was  assumed  that  the  latter  was  decomposed  ;  at  a 
