56 
Dairy  Cattle  and  the  Butter  Test. 
this,  it  is  conceivable  that  the  churnability  of  the  milh  might 
be  affected  by  the  quantities  of  these  substances  present. 
Support  is  lent  to  this  hypothesis  by  the  fact  that  a sour 
sample  of  a milk  will  churn  more  readily  than  a fresh  sample 
of  the  same  milk,  from  which  it  would  appear  that  the 
conversion  of  a portion  of  the  lactose  into  lactic  acid  and 
the  resultant  partial  precipitation,  in  an  inert  form,  of  the 
casein,  reduces  the  quantities  of  these  emulsifying  agents  in 
Fig.  11.— Dexter.  Milk  x 500  diam. 
the  milk  and  thus  facilitates  the  de-emulsifying  operation  of 
churning. 
The  remaining  factor  which  might 'influence  chui’nability 
is  the  character  of  the  fat-globules,  and  it  is  to  this  that  we 
have  more  particularly  turned  our  attention,  with  the  results 
tabulated  in  the  foregoing  pages.  We  had  hoped  that,  from 
the  comparison  between  our  figures  and  the  tabulated  results 
of  the  Butter  Test  supplied  by  Mr.  Mathews,  it  would  have 
