320 THE BLOOD. 



the womb and the vagina, so that only fluid cruor is at times eliminated, 

 and in part on a contamination with vaginal mucus, which disturbs the 

 coagulation. Menstrual blood, according to GAUTIER and BOURCET, 

 contains arsenic and is also richer in iodine than other blood (see Blood- 

 serum, page 261). 



The Blood of the Two Sexes. Women's blood coagulates somewhat 

 more quickly, has a lower specific gravity, a greater amount of water, 

 and a smaller quantity of solids than the blood of man. The amount 

 of blood-corpuscles and haemoglobin is somewhat smaller in woman's 

 blood. The amount of haemoglobin is 146 p. m. for man's blood and 133 

 p. m. for woman's. 



During pregnancy NASSE has observed a decrease in the specific gravity, 

 with an increase in the amount of water, until the end of the eighth month. 

 From then the specific gravity increases, and at delivery it is normal 

 again. The amount of fibrin is somewhat increased (BECQUEREL and 

 RODIER, NASSE). The number of blood-corpuscles seems to decrease. 

 In regard to the amount of haemoglobin the statements are somewhat 

 contradictory. COHNSTEIN found the number of red corpuscles diminished 

 in the blood of pregnant sheep as compared with non-pregnant, but the 

 red corpuscles were larger and the quantity of haemoglobin in the blood 

 was greater in the first case. MOLLENBERG l found in most cases an 

 increase in the amount of haemoglobin in pregnancy in the last months. 



The Blood at Different Periods of Life. Foetal and infant blood is 

 richer in erythrocytes and haemoglobin than the blood of the mother. 

 The highest percentage of haemoglobin in the blood has been observed 

 by several investigators, such as COHNSTEIN and ZUNTZ, OTTO, WINTER- 

 NITZ, ABDERHALDEN, SCHWINGE, and others, immediately or very soon 

 after birth or at least within the first few days. In man, two or three 

 days after birth the haemoglobin reaches a maximum (200-210 p. m.) 

 which is greater than at any other period of life. This is the cause of 

 the great abundance of solids in the blood of new-born infants, as observed 

 by several investigators. The quantity of haemoglobin and blood-cor- 

 puscles sinks gradually from this first maximum to a minimum of about 

 110 p. m. haemoglobin, which minimum appears in human beings between 

 the fourth and eighth years. The quantity of haemoglobin then increases 

 again until about the twentieth year, when a second maximum of 137- 

 150 p. m. is reached. The haemoglobin remains at this point only to 

 about the forty-fifth year, and then gradually and slowly decreases 

 (LEICHTENSTERN, OTTO 2 ). According to earlier reports, the blood at 



1 Nasse, Maly's Jahresber., 7; Becquerel and Rodier, Trait de chim. pathol., 

 Paris, 1854; Cohnstein, Pfliiger's Arch., 34, 233; Mollenberg, Maly's Jahresber., 31, 

 185. See also Payer, Arch. f. Gynak., 71. 



2 Cohnstein and Kuntz, Pfluger's Arch., 34; Winternitz, Zeitschr. f. physiol. Chem., 



