112       MOLECULAR  DISSYMMETRY  OP  ORGANIC  PRODUCTS. 
in  every  fermentation,  properly  so  called,  there  is  a  substance 
which  is  chemically  transformed,  and  correlatively,  there  is  a 
development  of  a  body  possessing  the  manners  of  a  mycodermic 
vegetable.  Elsewhere,  and  it  is  this  which  it  is  important  to 
note  at  this  time,  the  yeast  which  causes  the  right  salt  to  fer- 
ment, respects  the  left  salt,  in  spite  of  the  absolute  identity  of 
the  physical  and  chemical  properties  of  the  two  right  and  left 
tartrates  of  ammonia,  whenever  they  are  not  subjected  to  dis- 
symmetric actions. 
Observe  then  molecular  dissymmetry  proper  to  organic  mat- 
ters intervening  in  a  phenomenon  of  the  physiological  order, 
and  it  intervenes  here  in  its  character  of  modifier  of  chemical 
affinities.  There  is  not  the  least  doubt  in  the  world  about  what 
may  be  the  kind  of  dissymmetry  proper  to  the  molecular  arrange- 
ment of  left  tartaric  acid,  which  is  the  sole,  exclusive  cause  of 
the  difference  that  it  presents  with  the  right  acid,  under  the  re- 
lation of  its  fermentation. 
And  thus  is  found  introduced  into  physiological  considera- 
tions and  studies  the  idea  of  the  influence  of  the  molecular  dis- 
symmetry of  natural  organic  products,  of  the  great  character 
which  establishes,  perhaps,  the  only  well-marked  line  of  demarca- 
tion, which  can  be  placed  at  the  present  time  between  the  che- 
mistry of  organic  nature  and  the  chemistry  of  inorganic  nature. 
XIII. 
Such  are,  gentlemen,  in  their  totality,  the  labors  with  which 
I  have  been  charged  to  entertain  you. 
You  have  learned,  as  we  advanced,  why  I  have  entitled  my 
exposition,  On  the  Molecular  Dissymmetry  of  Natural  Organic 
products.  It  is,  in  fact,  the  theory  of  molecular  dissymmetry 
that  we  have  just  established;  one  of  the  highest  chapters  of 
science,  entirely  unforeseen,  and  which  offers  to  physiology  en- 
tirely new,  distant,  but  certain  horizons. 
I  entertain  this  opinion  of  the  results  of  my  own  researches, 
without  mingling  in  the  expression  of  my  thought  any  of  the 
self-satisfaction  of  the  author.  May  it  please  God  that  per- 
sonalities shall  never  be  possible  in  this  chair  !  These  are  as 
pages  of  the  history  of  chemistry,  which  we  shall  successively 
write,  with  the  sentiment  of  dignity  which  a  true  love  of  science 
always  inspires. 
