TABLE VIII.MILK OF WOMEN FROM THE 31ST TO 91ST DAY OF No. of sample. Ab've Bel'w Ab've Bel'w Ab've Bel'w Ab've Bel'w Ab've Bal'w Above Below TABLE IX.-MILK OF WOMEN FROM THE 91ST DAY TO THE 10TH No of sample. Day. Ab've Bel w Ab've Bel'w Ab've Bel'w Ab've Bel'w Ab've Bel'w Above Below IV. Nationality.-The statistics are entirely too meagre to determine the influence of nationality. It would be necessary to obtain for each race a large collection of results, in which the other causes of variation, like age, period of lactation, etc., were allowed for or eliminated. This has never been done, and would require, not eighty, but many hundred, analyses. The difficulty of generalization upon these points can be most forcibly illustrated by comparing the analysis of sample No. 40, which was obtained from a negress, with the other samples, and with the general average. Neither in color, smell, nor other physical characteristics, nor in chemical constitution, was this one sample so markedly different from the others as to be put, as some have proposed to do with the milk of negro women, in a class by itself. V. Physical Constitution of the Mother.-A comparison of the physical characteristics of the mother, whether blonde or brunette, or more minutely, as to color of eyes, hair, complexion, etc., has not shown that these differences are necessarily related to corresponding differences in the composition of the milk. But actual differences in the physical condition of the mother are intimately related. The samples obtained from women of over-robust habit were not so rich in albuminoids as those from pronouncedly anæmic women; and, generally speaking, the best milk was obtained from lean women in good physical condition. Graphic Chart.-A great deal of labor was devoted to the preparation of a graphic chart of the results of the analyses performed during the course of the present investigation. It was thought that the study of such a chart might reveal some law governing the relative amounts of the various constituents, which law might escape notice in comparing merely tabulated figures. The chart represents the results grouped according to the period of lactation, and follows the same order as that of Table I. In case, however, a number of samples were obtained from the same mother on different dates, these analyses are represented consecutively. These exceptions to the general order of arrangements are to be noted in samples 7, 18, 28, and 35, in samples 15, 16, 26, 29, and 30, and in samples 1 and 17. The horizontal lines in the chart represent differences of one-fifth of one per cent; the vertical columns represent the sample analyzed. One feature the chart exhibits in the most striking manner, and that is the great variability in the constitution of women's milk. The proportion of fat more especially varies in an exceedingly arbitrary manner. But as to any fixed and definite relation governing the proportion of the constituents to each other, or to the sum total of the solid constituents, the graphic chart thus far has failed to afford a satisfactory indication. TITLES OF OTHER PAPERS READ IN SECTION C. MODIFICATIONS OF RUFFLE'S METHOD FOR THE ABSOLUTE DETERMINATION OF NITROGEN. By Prof. H. C. WHITE, University of Georgia, Athens, Georgia. ON THE ASSIMILATION OF ATMOSPHERIC NITROGEN BY PLANTS. By Prof. W. O. ATWATER, Wesleyan University, Middletown, Conn. NOTES ON REINSCH'S TEST. By Dr. HENRY LEFFMANN, Philadelphia, Pa. APPARATUS FOR THE DETERMINATION OF NITROGEN BY THE COPPER OXIDE METHOD. By Dr. CHARLES W. DABNEY, jr., Director of the N. C. Agricultural Experiment Station, Raleigh, N. C. A CONVENIENT APPARATUS FOR DETERMINING NITROGEN IN DUPLICATE. By Dr. CHARLES W. DABNEY, jr., Director of the N. C. Agricultural Experiment Station, Raleigh, N. C. ANHYDROBENZOAMIDOSALICYLIC ACID. By Dr. CHARLES W. DABNEY, jr., Director of the N. C. Agricultural Experiment Station, Raleigh, N. C. TORSION BALANCES. By Dr. ALFRED SPRINGER, Cincinnati, Ohio. DISCUSSION ON FERMENTATION. By Dr. ALFRED SPRINGER, Cincin nati, Ohio. ON A SUBSTITUTE FOR LITMUS AND SIMPLE PROCESSES FOR ESTIMATING ALKALIES, ACIDS, TEMPORARY HARDNESS OF WATER, ETC. land. By J. F. HEYES, M. A., Christ College, Brecon, Eng A NEW FORM OF GAS REGULATOR. By Prof. F. P. DUNNINGTON, University of Virginia, Va. SIMPLE LECTURE ILLUSTRATIONS. University of Virginia, Va. PRODUCTION OF ARGENTIC HYDRATE. By Prof. F. P. DUNNINGTON, By Prof. F. P. DUNNINGTON, IMPROVEMENTS IN APPARATUS FOR RAPID GAS ANALYSIS. By Dr. ARTHUR H. ELLIOT, School of Mines, Columbia College, New York, N. Y. |