18 Testing Mm and Its Products. 



Mineral Components of Milk. 



In per cent, of Milk. In per cent, of Ash. 



Potassium oxid (K 2 O) 19 per ct. 25.64 per ct. 



Sodium oxid (Na 2 O) 09 12.45 



Lime(CaO) 18 24.58 



Magnesia (MgO) 02 3.09 



Iron oxid (Fe 2 O 3 ) 002 .34 



Phosphoric anhydrid (P 2 O 5 ). .16 21.24 



Chlorin (Cl) .12 16.34 



.762 per ct. 103.68 per ct. 

 Less oxygen, corresponding to 



chlorin... . .012 3.68 



.75 perct. 100.00 per ct. 



The combinations in which the preceding bases and 

 acids are contained in the milk are not known with cer- 

 tainty. According to Soldner, 36 to 56 per cent, of the 

 phosphoric acid found in milk, and from 53 to 72 per 

 cent, of the lime, are present in suspension in th*i milk 

 as di- and tri-calcium phosphates, and may be filtered 

 out by means of Chamberland filters (18), or by long 

 continued centrifuging (Babcock 1 ), The rest of the ash 

 constituents are dissolved in the milk serum. 



The ash content of normal cows' milk varies but little, 

 as a rule only between .6 and .9 per cent., with an 

 average of .7 per cent. Milk with a high fat content 

 generally contains about .8 per cent, of ash; strippers' 

 milk always has a high ash content, at times even ex- 

 ceeding one per cent. Ordinarily, the mineral constitu- 

 ents are, however, the components of milk least liable 

 to variation. 



21. Other Components. Besides the milk constituents 

 enumerated and described in the preceding pages, nor- 



1 Wis. Experiment Station, twelfth report, p. 93. 



