12 Proteins of Cow’s Milk 
no visible particles. On heating to 72° a flocculent coagulum 
formed which separated so imperfectly that centrifugation was 
necessary for its removal. The deposit was washed free from 
sulfate by centrifuging several times with water, then with 
50 per cent alcohol, dehydrated with absolute alcohol, extracted 
with ether, and dried over sulfuric acid. This preparation 
weighed 2.4 gm. and contained 8.55 per cent of moisture (dried 
at 110°) and 2.12 per cent of ash. This is equivalent to 0.52 
gm. of moisture- and ash-free globulin per liter of whole milk, 
assuming that 1 liter of whole milk is equivalent to 965 cc. of 
skimmed milk. Ash- and moisture-free, this preparation had the 
following composition: 
Lactoglobulin Free from Lactalbumin. 
I II Average. 
Carbon. Jo)3 cee RBI et ee 51.92 51.85 51.88 
Hey drogen yim whee ce cin ee eee ae 7.01 6.88 6.96 
Nitrogen ies eek bok ae cc cea ee ee eee 15.47 15.40 15.44 
Sulfur® Settee ae orck oe ee cee eee eee 0.86 0.86 
Phosphorus?) 2923570. a ee 0.24 0.24 
Oxygen (by citeren oa sla svete LN RG ER ns ee 24.62 — 
100.00 
Since all of the phosphorus contained in this preparation was 
recovered in the ash, special investigation was required to de- 
termine whether this belonged to phosphatides, to contaminat- 
ing phosphates, or to other phosphorus-containing substances. 
Accordingly another preparation was made from 6 liters of 
centrifugated milk in the same way up to the point of final pre- 
cipitation with magnesium sulfate. When freed from almost 
all of the adhering solution by pressing with filter paper, it 
was reduced to a fine powder and digested for a long time, with 
absolute alcohol. Dried over sulfuric acid this preparation 
weighed 7.72 gm. and contained 7.21 per cent of nitrogen, equal 
to 3.6 gm. of globulin, the balance being magnesium sulfate and 
water. The alcoholic extract when’ evaporated left a residue 
weighing 0.1960 gm., thus making the total amount of the magne- 
sium sulfate precipitate 7.92 gm. The residue from the alcoholic 
