DAIRY PRODUCTS. 



109 



The numbers obtained by extraction with alcohol are taken as the 



siy of comparison, not because I believe them to be more reliable, but 

 because that method is the one generally employed in the estimation of 

 milk sugar. 



In the alcohol extraction the milk was evaporated to dryiiess in a thin 

 glass capsule, the dish and dried residue pulverized in a mortar, washed 

 with ether into a continuous extraction apparatus, exhausted with eiher, 

 and then with 80 per cent, alcohol for ten hours. 



Duplicate analyses are indicated in the table by the small brackets. 



TABLE No. 9. Percentage of milk sugar. 



Remarks on Table No. 9. The results obtained by using various other 

 reagents for the precipitation of the caseine, viz, MgSO 4 , CuSO 4 , HOI, 

 &c., have not been entered in the table. In none of these cases was 

 there sufficient encouragement to warrant an extended trial. In most 

 cases the precipitation was slow or imperfect, and the nitration difficult. 



One important fact should not be overlooked, viz, that any excess of 

 basic plumbic acetate causes a rapid decrease in the rotatory power of 

 the solution ; whether this decrease is. due to precipitation of the sugar 



