604 
Linseed  Oil. 
Am,  Jour.  Pharm. 
Dec,  1887. 
the  equivalent  of  this  acid  being  292'7,  and  thus  it  would  compose 
almost  entirely  the  acid  present  in  the  oil  as  glyceride. 
In  the  last  number  of  the  Ber.  d.  D.  Chem.  Ges.,  page  2735,  is  an 
article  by  Messrs.  Norton  and  Richardson,  of  Boston,  in  which  is 
stated  "  that  in  drying  linoleic  acid  in  an  atmosphere  of  hydrogen  at 
100°C,  we  found  it  impossible  to  obtain  a  constant  weight;  after  sixty- 
eight  hours'  drying,  20*36  per  cent,  of  the  acid  taken  had  been  vola- 
tilized, and  the  residue  was  still  losing.  No  decomposition  had 
taken  place,  as  was  found  by  analysis.  Convinced  that  linoleic  acid 
was  volatile,  we  succeeded  in  distilling  it  at  a  temperature  of  290°C, 
and  a  pressure  of  89  mm.  The  distillate,  amounting  to  75  per  cent,  of 
the  acid  present  in. the  oil,  was  a  colorless  liquid,  had  a  specific  gravity 
0-9108  at  15°  C,  and  the  formula,  C20H36O  2,  agreeing  with  the  vapor 
density  which  we  found  to  be  J  53.  The  residue  has  not  yet  been 
examined." 
The  saponification  equivalent  of  the  glyceride  of  this  acid — 
C20H36O2 — is  320'7  ;  higher  than  the  equivalent  of  linseed-oil  (287  to 
300) ;  so  it  is  evident  the  non- volatile  acid  present,  amounting  to  25 
per  cent.,  must  have  a  smaller  equivalent,  which  can  not  be  above 
240,  and  which  would  correspond  to  an  acid  of  the  same  series  con- 
taining fourteen  carbon  atoms,  or  CuH2402.  The  volatile  acid  of 
Messrs.  Norton  and  Richardson  corresponds  to  the  acid  which  I  found 
does  not  saponify  with  barium  carbonate ;  while  the  acid,  forming  a 
barium  salt,  will  be  found  in  the  residue  from  their  distillation  of  the 
volatile  acid. 
As  opportunity  offers,  I  will  isolate  this  acid  and  establish  its 
formula  by  ultimate  analysis. 
A  Mercurial  Potash  Soap  as  a  Sorbefacient.— Svetukhin 
(Russk.  Medits. ;  N.  Y.  Med,  Jour.,  Aug.  27,  1887),  finds  a  preparation  termed 
sapo  kalinus  hydrargyrosus,  made  by  mixing  metallic  mercury,  mercurial 
ointment,  caustic  potash,  and  olive-oil  in  certain  proportions — the  resulting 
soap  containing  a  third  of  its  weight  of  mercury — an  advantageous  appli- 
cation for  promoting  the  absorption  of  pleuritic  effusion.  It  is  said  to  be 
more  easily  rubbed  in  than  mercurial  ointment,  less  irritating  to  the  skin, 
and  not  so  rapidly  productive  of  stomatitis.  From  half  a  drachm  to  a 
drachm  is  agitated  with  hot  water,  so  as  to  form  a  good  froth,  and  lightly 
rubbed  into  the  skin.  In  cases  of  simple  watery  effusion,  an  effect  may  be 
detected  after  from  six  to  ten  inunctions,  and  after  twenty  the  water  is 
usually  found  to  have  wholly  disappeared. 
