Am.^our.jharm.  j     Comparative  Test  of  Antiferments.  63 
The  form  and  appearance  of  the  cells  of  these  solutions,  with  one  ex- 
ception (ii)  were  such  as  characterized,  those  of  Saccbaromyces  Cerevisia?, 
while  in  E  the  cells  more  closely  resembled  those  of  Saccbaromyces 
Mycoderma  as  did  the  method  of  budding  also.  Still,  it  could  scarcely 
be  this  plant  as  the  liquid  certainly  was  in  the  flood  tide  of  active 
fermentation.  No  difference  was  observed  in  the  appearance  of  the 
surface  or  the  sedimentary  ferments,  excepting  in  the  former  the  bud- 
ding seemed  more  rapid.  F,  G,  iZ,  /,  upon  examination,  proved  to 
be  all  slightly  sour  ;  no  appearance  of  froth,  however,  being  seen. 
Under  the  microscope  were  to  be  seen  a  few  fresh,  plump  cells,  and  a 
few  larger  withered  cells,  while  these  liquids  had  also  grown  muddy  in 
appearance  from  the  production  of  fresh  cells. 
At  the  expiration  of  twenty-four  hours  the  solutions  were  again 
examined. 
A,  Z?,  C,  Z),  Ey  y,  K,  L,  M  were  quite  sour  ;  they  were  covered  with 
froth  and  rapidly  proliferating  cells,  while  bubbles  of  carbon  dioxide 
could  be  seen  to  constantly  rise  to  the  surface  of  the  liquid.  In  y, 
X,  Z,  M  the  deep  brown  color  had  been  reduced  to  a  yellowish  white 
through  the  action  of  the  dissengaged  sulphurous  acid  from  the  calcium 
bisulphite ;  F,  G,  /  were  scarcely  changed.  They  were  rather 
more  sour  than  at  the  previous  examination  and  although  full  of  bac- 
teria, there  were  very  few  cells  to  be  seen,  and  those  few  were  very 
small  and  shriveled  in  appearance.  Another  marked  difference  be- 
tween these  four  solutions  containing  the  benzoic  acid  is  in  the  fact  that 
no  froth  is  formed  on  these,  while  in  the  others  the  froth  is  from  one- 
eighth  to  one-fourth  the  depth  of  the  liquids. 
In  this  series  of  experiments,  therefore,  the  benzoic  acid,  while  not 
entirely  preventing  fermentation,  had  a  very  much  more  marked  influence 
in  arresting  and  aborting  this  change  than  did  either  the  calcium  bisul- 
phite or  salicylic  acid. 
A  further  experiment  is  in  progress  upon  solutions  of  cane  sugar  in 
the  form  of  dilute  syrups.  We  have  nothing  to  report  excepting  that 
the  unprotected  sample  has  developed  a  large  amount  of  a  confervoid 
growth,  the  striae  consisting  of  rods  of  simple  elongated  cells,  with  no 
appearance  of  fermentation,  while  the  samples  protected  by  either  sali- 
cylic or  benzoic  acid  are  at  the  present  writing  unchanged. 
Philadelphia,  First  mo.  3,  1878. 
