OIL  OF  THE  DUGONG  A  SUBSTITUTE  FOR  COD-LIVER  OIL.  335 
also  that  the  most  considerable  sources  of  loss  obtained  in  the 
case  of  that  portion  of  yeast  which  weighed  the  most.  This 
curious  and  unexpected  result  admits  of  the  explication  of  a  fact 
which,  at  the  outset  of  M.  Pasteur's  investigations,  caused  him 
much  surprise.  When  yeast  is  exhausted  in  contact  with*  a  solu- 
tion of  pure  sugar,  it  is  admitted  that  the  whole  of  its  nitrogen 
passes  into  the  state  of  an  ammoniacal  salt.  In  reality  the 
quantity  of  ammonia  produced  during  the  fermentation  is  exces- 
sively minute,  and  very  much  less  than  that  which  should  be 
obtained  in  order  to  account  for  the  diminution  of  the  amount 
of  nitrogen  in  the  yeast.  But  the  diminution  of  azote  is  only 
apparent.  It  is  due  to  the  augmentation  of  the  weight  of  the 
yeast  by  assimilation  of  sugar. 
The  inferences  to  be  drawn  from  the  preceding  facts  will  be 
sufficiently  evident.  The  transformation  of  sugar  into  alcohol 
and  carbonic  acid  must  be  regarded  as  an  act  correlative  with  a 
vital  phenomenon,  an  organization  of  globules  in  which  the  sugar 
takes  a  direct  part,  by  furnishing  material  for  their  production. 
Another  result  to  which  M.  Pasteur  attaches  great  importance, 
is  the  discovery  of  a  mode  of  fermenting  tartaric  acid  which 
affects  the  ordinary  dextro-tartaric  acid,  but  not  the  levo-tartaric 
acid.  Consequently,  when  paratartaric  acid,  consisting  of  a 
mixture,  molecule  for  molecule,  of  the  two  kinds  of  tartaric  acid, 
is  submitted  to  this  mode  of  fermentation,  the  paratartaric  acid 
is  decomposed  into  dextro-tartaric  acid,  which  ferments,  and  into 
levo-tartaric  acid,  which  remains  intact,  so  that  this  treatment  is 
the  best  means  of  isolating  the  levo-tartaric  acid. 
He  adds,  also,  that  the  products  of  the  fermentation  of  tar- 
taric acid,  compared  with  those  of  the  acids  obtained  by  the 
fermentation  of  ordinary  sugar,  and  joined  to  the  curious  rela- 
tions between  the  crystalline  forms  of  cane-sugar  and  dextro- 
tartaric  acid,  justify  the  opinion  that  cane-sugar  has  probably 
the  same  molecular  constitution  as  that  acid  London  Pharm. 
Jour.,  April  1,  1858. 
OIL  OF  THE  DUGONG  A  SUBSTITUTE  FOR  COD-LIVER  OIL. 
Australia  offers  us  an  oil  which  seems  likely  to  prove  a  most 
agreeable  and  efficient  substitute  for  cod-liver  oil.    A  cetaceous 
