ON  A  PURE  NATURAL  WATER. 
561 
until  the  fusing  point  was  stationary ;  it  now  fused  at  72-°5  C. 
(162.°5  b\),  and  congealed  at  67°  C.  (152°  F.)  Ultimate 
analysis  proved  it  to  have  the  composition  C42H4204.  The 
author  named  it  Medullic  Acid.  Voelcker's  acid  from  the 
behenoil  (from  the  Moringa  oleifera),  for  which  he  gives  the 
same  composition,  fuses  at  76°  C,  and  Strecker  has  already 
remarked  that  the  analyses  agree  better  with  the  formula 
0MH44O4,  which  is  rendered  probable  by  the  fusing  point  of  the 
medullic  acid. 
From  the  mother  liquors  obtained  from  the  re-crystallization  of 
the  medullic  acid  {  of  the  alcohol  was  distilled  off.  The 
crystalline  mass  was  repeatedly  crystallized  from  alcohol,  and 
fused  then  at  62°C.  (143.°6  F.)  and  then  congealed  at  55° -5  C. 
131 »° 9  F.)  ;  it  was  palmitic  acid.  The  mother  liquors  yielded 
a  small  portion  of  a  mixture  of  palmitic  and  oleic  acid,  fusing 
at  38°  C. 
The  filtrate  from  the  third  precipitate  with  acetate  of  magnesia 
was  mixed  with  the  remaining  fourth  of  the  alcoholic  solution  of 
this  salt,  and  evaporated  with  the  addition  of  water.  The 
magnesia  soap  was  decomposed  by  hydrochloric  acid,  the  fatty 
acid  combined  with  potassa,  the  soap  decomposed  by  chloride  of 
sodium,,  and  the  resulting  soda  soap  precipitated  by  acetate  of 
lead.  Ether  dissolved  from  it  87|  per  ct.  and  5-875  grs.  of  this 
soluble  portion  left  on  incineration  1-710  and  1-720  grs.  PbO; 
the  formula  PbO,  C36H3303,  requires  1.7047  grs.  The  acid  of 
this  soap  is  therefore  oleic  acid. 
No  stearic  acid  was  found. 
The  approximate  proportion  of  the  three  acids  in  ox  marrow 
is  :  palmitic  46,  medullic  10,  and  oleic  acid  44  per  ct. — Inau. 
(jural  Dissertation,  Wittsteins  V.  Leh.  ix.  330-340. — J.  m.  m. 
ON  A  PURE  NATURAL  WATER. 
By  B.  M.  Brackenridge,  of  Tarentuni,  Allegheny  County,  Pa. 
Spring  water  usually  contains  a  larger  or  smaller  amount  of 
gaseous  and  saline  bodies  in  solution  ;  rain  water  is  generally 
supposed  to  approach  nearest  to  distilled  water.  The  author, 
however,  gives  notice  of  an  exception  to  this  rule,  and  Dr. 
Ewd.  Stieren,  who  has  been  using  the  water  since  1852, 
confirms  his  statement. 
36 
