308 Report of the Department of Chemistry of the 



form at the rate of 50 c.c. per 1000 c.c. of milk and the fat removed by 

 means of a centrifugal machine; the removal of fat is necessary 

 since it clogs the pores of the filter. The fat-free milk was then 

 filtered through Pasteur-Chamberland filtering tubes. Analyses were 

 made of the milk and of the serum. We did not determine those 

 constituents present in milk only in traces, such as iron, sulphuric 

 acid, etc. 



Table I. — Constituents of Milk-Serum. 



Constituents. 



Sugar 



Casein 



Albumin 



Nitrogen in other com- 

 pounds 



Citric acid 



Phosphorus (organic and 

 inorganic) 



Phosphorus (inorganic) . . . 



Calcium 



Magnesium 



Potassium 



Sodium 



Chlorine 



Ash 



Sample No. 1. 



Original 



milk 



100 c.c. 



Grams. 



3.35 

 0.525 



Milk- 

 serum 

 100 c.c. 



0.125 

 0.096 

 0.128 

 0.012 



*0.354 



0.081 



Grams. 



o.oo' 



0.369 



0.067 

 0.067 

 0.045 

 0.009 



*0.352 



0.082 



Per- 

 centage 

 of milk 



con- 

 stituents 

 in serum. 



Per ct. 



oioo' 



70.29 



53.60 

 70.00 

 35.16 

 75.00 



99.44 



100.00 



Sample No. 2. 



Original 



milk 

 100 c.c. 



Grams. 

 5.75 

 3.07 

 0.506 



0.049 

 0.237 



0.087 

 0.144 

 0.013 

 0.120 

 0.055 

 0.076 

 0.725 



Milk- 

 serum 

 100 c.c. 



Grams. 

 5.75 

 0.00 

 0.188 



0.049 

 0.237 



0.056 

 0.048 

 0.007 

 0.124 

 0.057 

 0.081 

 0.400 



Per- 

 centage 

 of milk 



con- 

 stituents 

 in serum. 



Per ct. 

 100.00 

 0.00 

 37.15 



100.00 

 100.00 



64.40 



33.33 



53.85 



100.00 



100.00 



100.00 



55.17 



* As chlorides 



A study of the data contained in Table I enables us to show the 

 general relation of the constituents of milk to the constituents of 

 milk-serum. The following form of statement furnishes a clear 

 summary of the facts. 



2. Milk constituents partly 

 in solution and partly in 

 suspension or colloidal 

 solution : 



(a) Albumin. 



(b) Inorganic phos- 

 phates. 



(c) Calcium. 



(d) Magnesium. 



1. Milk constituents in 

 true solution in milk 

 serum : 



(a) Sugar. 



(b) Citric acid 



(c) Potassium. 



(d) Sodium. 



(e) Chlorine. 



3. Milk constituents entirely 

 in suspension or colloidal 

 solution: 



(a) Fat. 



(b) Casein. 



