FACTS  AND  THEORIES  OF  FERMENTATION. 
457 
slightly,  else  it  will  not  coagulate  ;  or  what  is  better,  warm  the 
mixture  of  milk  and  rennet  gently. 
On  the  other  hand — 
Take  Cream  of  tartar    .       .       .       .       .     2  grammes. 
Sugar  .       .       .       .       .       .  12 
Dried  albumen      .       .  2  " 
(or  better,  half  the  white  of  an  egg.) 
Put  the  curded  milk  in  a  saucepan,  cut  it  up  with  a  spatula, 
and,  by  means  of  a  gentle  fire,  heat  till  the  casein  separates 
from  the  serum,  which  requires  about  104°  Fan.  The  whole  is 
thrown  on  a  strainer  or  cullender  to  drain.  The  crude  whey  is 
then  put  in  a  silver  or  well  cleaned  copper  vessel,  the  particles 
of  casein  that  float  removed  with  a  skimmer,  and  then  heat  by 
a  quick  fire,  add  the  sugar,  and  when  nearly  boiling  introduce 
the  cream  of  tartar,  and  after  it  rises  throw  in  the  albumen,  pre- 
viously beaten  with  a  little  cold  water  or  old  whey  ;  allow  the 
liquid  to  boil  up  a  second  time,  and  then  immediately  remove  it 
from  the  basin  to  a  filter  previously  moistened  with  boiling  water. 
Repertoire  de  Pharm.,  Mai,  1855. 
AN  INVESTIGATION  INTO    THE    FACTS  AND  THEORIES  OF 
FERMENTATION  AND  PUTREFACTION. 
By  Henry  Pemberton,  Practical  and  Analytical  Chemist. 
[The  above  essay  appeared  in  the  May  number  of  the  Medical  Exami- 
ner, but  being  too  voluminous  for  transfer  to  our  pages  entire,  we  give 
an  extract  which  more  particularly  embraces  the  experimental  observa- 
tions of  the  writer. — Ed.  Am.  Jour.  Pharmacy  ] 
Schroder  and  Yon  Dusch*  have  lately  given  the  details  of  ex. 
periments  tried  by  them  upon  the  effects  produced  by  filtered 
air  upon  fermentation,  etc.  They  have  established  the  fact, 
"  that  when  air  is  passed  through  a  tube  filled  with  raw  cotton, 
moderately  compressed,  it  becomes  incapable  of  inducing  fer- 
mentation or  putrefaction  in  substances  that  would  rapidly  un- 
^Liebig's  Annalen,  1854,  and  Medical  Examiner,  June,  1854. 
