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Des diagrammes obtenus lors des recherches electrophoretiques de serum sanguin d'apres Tiselius avec differentes solutions tampons, il apparait qu'une bonne separation entre l'albumine et la globuline α1 est determinee par le pH, qui doit etre de 8,6 a 8,9. Il apparait egalement qu'une bonne separation entre la globuline γ2 et le delta, depend de la concentration en ions a mobilite reduite. Dans la pratique on donnera la preference soit au tampon modifie de Michaelis, soit au tampon de Longsworth d'apres notre modification (Tableau I - Solutions 3 et 5). Lors de l'emploi du tampon original de Longsworth (Tableau I - Solution 4) on obtient egalement une bonne separation de la globuline α1 et du delta, mais les electrodes doivent etre couvertes d'une solution de chlorure de sodium, ce qui occasionne certains desavantages.

Different enzymes have been determined in 10 samples of human colostrum and 10 samples of human normal milk. From the results, it appears that the activity of pyrophosphatase, protease, trypsin inhibitor, catalase, and peroxydase is greater in colostrum than in normal milk, while the reverse is true for adenosinetriphosphatase and pseudocholinesterase. Furthermore, it appears that the activity of adenosinetriphosphatase is 23 times greater in human normal milk than in normal cow milk, catalase 10 times, pseudocholinesterase 9 times, and protease 3 times, while trypsin inhibitor is the same in the two milks. The activity of the pyrophosphatase and especially of peroxydase is lower in human than in cow milk. Finally, different correlations have been established between some enzymes, and a micro-method for protein determination in human milk with amido black has been established.

Lecithin, kephalin, sphingomyelin, glycerides and free and esterified cholesterol have been determined in udder lymph and plasma of the udder veins. Expressed in absolute values, each lipid fraction occurs in a significantly lower concentration in lymph than in plasma. Expressed as a percentage of total lipids however the phospholipids occur in a lower and the cholesterolesters in a higher proportion in lymph than in plasma. The lecithin expressed as a percentage of total phospholipids is lower in lymph than in plasma, while the reverse is true for the sphingomyelin; the kephalin proportion is the same in the two fluids. It is striking that fatty acids and phospholipids, two classes of lipids removed from the blood by the mammary gland, comprise a lower proportion of the total lipids in the lymph than in the plasma. Correlations between the various lipid fractions of the udder lymph and plasma are discussed.

Udder lymph resembles the lymph draining most other organs in its content of lipid, protein and glycoprotein. The composition of the lymph is apparently more variable than that of the plasma. Protein and lipid occur in lower concentrations in lymph than in plasma. The concentration of phospholipid in udder lymph is, however, very low and is significantly reduced when compared with the other lipid or the glycoprotein constituents. It is possible that this is connected with milk synthesis.

L'electrophorese et le fractionnement chimique furent effectues sur des laits et leurs serums obtenus en soumettant le lait a des forces centrifuges 7000 a 38000 fois superieures a la pesanteur. De nos resultats, il ressort que dans les serums obtenus avec des forces centrifuges croissantes, la caseine et les fractions electrophoretiquesB, C etG diminuent, alors que l'albumine et la globuline de meme que les fractionsD, E etH augmentent. Il en resulte egalement que les fractionsB, C etG correspondent a la caseine (G est plus stable vis-a-vis de la force centrifuge queB),D etE a la lactalbumine totale etH a la globuline. Il est possible que la fractionA soit identique au composantn deMoore etLynn,B a la caseine alpha,D a la beta lactoglobuline dePalmer etG a la caseine beta.

Urea and uric acid were determined chemically and 10 amino acids chromatographically in udder lymph and plasma of the udder veins of cattle. From the results, it appears that urea occurs in the same concentration in the two fluids while uric acid and each of the 10 amino acids are considerably higher in the lymph than in the plasma. As a percentage of total amino nitrogen however, glycine and tyrosine occur in a significantly ( P = 0.01) lower concentration in lymph than in plasma, while the reverse is true for the leucines, lysine and also for threonine, but only at P = 0.05 for the latter. Highly significant correlations have been established between glycine, leucines and valine in lymph and in plasma.

Electrophoresis tests were carried out on samples of colostrum of dairy cows. The milk was first cleared by dialysis against Michaelis veronal-sodium buffer (pH = 8; μ = 0.1) and high-speed centrifuging. The results of chemical fractionation by the method of Rowland show an increase in the casein, in the samples from cow A, from 42.1 to 82.8%; with cow B from 29.7 to 81.0%. Together with this increase in casein content there is a drop in globulin content during the colostrum period from 41.7 to 4.5% with the samples of cow A and from 61.2 to 6.4% with cow B. In the electrophoresis (pH = 8; μ = 0.1; t = 2° C; I = 25 mA) the same number of fractions were obtained as with normal milk, but in different proportions. From the results obtained it appears that the B component, of mobility 7.5 · 10 −5 , rises during the colostrum period from 21.8 to 51.8% and from 11.9 to 48.6% respectively for the samples from cow A and B. The G component also, of mobility 3.6 · 10 −5 , rises during the colustrum period, i.e. from 9.0 to 14.7% in the samples from cow A, and from 6.5 to 18.4% with cow B. As we were able to establish previously from the results obtained in the electrophoresis of normal milk, the B and G components show a casein character, which is also confirmed by the results obtained with colostrum milk. Moreover, during the colostrum period there is a considerable drop in the H component, the slowest moving fraction with a mobility of 1.9 · 10 −5 . With the samples from cow A this drop is from 46.9 to 3.3% and with cow B from 59.2 to 4.2%. On account of the remarkable agreement between the globulin percentage and the magnitude of the H component, we ascribe a globulin character to this fraction. The other components A,C,D,E and F show only slight variations during the colostrum period.

Hydrocortisone, corticosterone, protein-bound iodine and inorganic iodine have been determined in udder lymph and plasma of the udder veins. Hydrocortisone in absolute value and in percentage of total steroids is lower in lymph than in plasma, while corticosterone occurs in practically the same concentration in the two fluids. Protein-bound iodine expressed in absolute values and as a percentage of total iodine, occurs in lower concentration in lymph than in plasma, but more iodine per g. protein is bound in lymph. A positive correlation has been established in udder lymph between the hydrocortisone and the protein-bound iodine.