48 THE AMERICAN JOURNAL OF SOCIOLOGY
man, 0,0511 for woman, and Schmidt, Scherer, and others give similar results. Welcker (using a chronometer) found between the corpuscles of man and woman the relation of 5 to 4.7, and 1 1 ay em confirmed this by numeration. Cadet found in woman on the average 4.9 million corpuscles per the cmm., and in man 5.2 million. More recently Korniloff, using still another method the spectroscope of Vierordt has reached about the same result. The proportion of red blood corpuscles varies according to individual constitution, race, and sex. In robust men Lacanu found 136 red corpuscles in 1000, in weak men only 116 in 1000; in robust women only 126 in 1000, and in weak women 1 17.* Professor Jones has taken the specific gravity of the blood of above 1500 individuals of all ages and of both sexes. 2 An examination of his charts shows that the specific gravity of the male is higher than that of the female between the ages of 1 6 and 68. Between the ages of 16 and 45 the average specific gravity of the male is about 1058, and that of the female about 1054.5. At 45 years the specific gravity of the male begins to fall rapidly and that of the female to rise rapidly, and at 55 they .are almost equal, but the male remains slightly higher until 68 years, when it falls below that of the female. The period of .marked difference in the specific gravity of the blood is thus seen to be coincident with the period of menstruation in the female. A chart constructed by Leichtenstern, based upon observations on 191 individuals and showing variations in the amount of haemoglobin with age, is also reproduced by Professor Jones, suggesting that the variations in specific gravity of the blood with age and sex are closely related to variations in the amount of haemoglobin. Leichtenstern states that the excess in men of haemoglobin is 7 per cent, until the tenth year, 8 per cent, between u and 50 years, and 5 per cent, after the fiftieth year. 3 Jones states further 4 that the specific gravity is higher
1 J. HAYEM, Du Sang et de ses alterations anatomiques, pp. 184-5.
- E. LLOYD JONES, " Further Observations on the Specific Gravity of the Blood in
Health and Disease," Journal of Physiology, Vol. XII, pp. 299 seq.
3 O. LEICHTENSTERN, Untersuchungen iiberden Haemoglobulingehaltdes B/utes,p. 38. 4 Pp. 316 seq.
