116 
C Immobility  of  Cream. 
all  the  micro-pliotographs  taken  was  ‘23  per  cent.,  or  less  than 
one  in  four  hundred. 
The  main  object  of  these  experiments,  however,  was  to 
see  whether  any  explanation  of  the  variations  in  the  churn- 
ability  of  different  creams  could  be  discovered,  the  method  of 
photographing  the  milks  from  which  the  creams  were  obtained 
being  only  an  incident  in  the  investigation.  It  actually 
proved  very  useful,  however,  as  it  helped  to  get  the  negative 
Fig.  2.— Apparatus  for  recording  Length  and  Number  of  Strokes  whilst  churning. 
result  referred  to  later.  The  method  may  prove  of  use,  it  is 
hoped,  for  further  investigations. 
Individual  Variation. 
An  important  question  to  decide,  before  it  is  possible  to 
conduct  exhaustive  experiments,  is  that  of  the  amount  of 
the  individual  variations  which  exist  in  samples  of  milk  obtained 
PENCIL 
LEVER 
ROCKI 
LEVER 
PLUNGER- ^ 
PENCIL 
PAPER 
PAPER 
