22 
is ashed the added calcium salts will cause an increase in the alka- 
linity of the ash, and especially in the percentage of calcium oxicl in 
the salt-free ash. It should be noted, however, that the alkalinity of 
a butter made from limed cream, or even of one washed in lime water, 
might be less than that of a natural butter with a high whey content, 
but an increase in the percentage of calcium oxid in the salt-free ash 
would at once reveal the use of lime at some stage. Perhaps by de- 
termining the ratio of alkalinity to another constituent of the butter 
ash, for example, phosphorus pentoxid, an independent method might 
be developed for detecting neutralization. It might be necessary to 
distinguish between a butter made from limed cream and a butter 
given a " lime bath." If the alkalinity were below 20, the reaction 
of a water extract acid to litmus, and the percentage of calcium oxid 
in the salt-free ash, corrected for calcium sulphate in the salt, well 
above 25, the use of a limed cream would be indicated. If, on the 
other hand, a butter had an alkalinitv of over 20. if the percentage of 
calcium oxid in the salt-free ash was over 35, if its water extract was 
alkaline to litmus, and if it gave a peculiar foam test and liberated 
butyric acid on the addition of dilute sulphuric acid, it would be 
strong evidence that lime had been added to the butter and not to 
the cream. 
SUMMARY. 
The percentage of calcium oxid in the ash of milk, unneutralized 
cream, and butter made from unneutralized cream varies within 
fairly narrow limits, with a tentative maximum set at 25. 
When lime has been added to the cream in the process of manu- 
facture this percentage is increased above 25, the increase varying 
with the amount of lime added and the degree of washing. 
The effect of calcium impurities in the salt has been studied and a 
method developed to correct for the chief impurity, calcium sulphate. 
It has been shown that the percentage of calcium oxid in the salt- 
free ash of butter made from unneutralized cream will not exceed the 
tentative maximum limit of 25, unless high percentages of salt with 
much impurity are employed. 
Finally, attention has been called to a form of sophistication of 
butter by chemical renovation. 
