222 ORGANIC AGRICULTURAL CHEMISTRY 



ferrous bromide. The amount of haemoglobin in fresh blood 

 is about 14 per cent. As previously stated, the amount of 

 blood is about 7.5 per cent of the body weight. A man of 68 

 kilograms (150 lbs.) would, therefore, have approximately 5100 

 grams of blood containing 714 grams of haemoglobin. The 

 oxygen-absorbing power of haemoglobin has been determined 

 as 1.34 c.c. oxygen per gram of haemoglobin. The total oxygen- 

 carrying power of the blood of an adult man would, therefore, 

 be about 950 c.c. Oxyhaemoglobin may be crystallized, and it 

 has been found that the crystal form varies with different species 

 of animals. 



The shape and size of erythrocytes vary with different ani- 

 mals. In man the size is about -3^=0^ of an inch, in the ele- 

 phant 27V0 of ^^ inch, in the ox X2V0' ^^ ^-n inch, and in the 

 musk deer ^ ^ 3 o of an inch. 



The number of erythrocytes is very large and has been shown 

 to vary with marked changes in condition. In the adult human 

 male the number is about 5,500,000 per cubic millimeter, in 

 the female about 4,500,000. Under abnormal conditions 

 affecting the rate of oxidation in the tissues, as after physical 

 exertion^ or at high altitudes, the number has been found to 

 increase to 7,000,000, and in pathological cases as high as 

 11,000,000. Under conditions of decreased oxidation, as in the 

 disease known as ancemia, the number has been found to fall to 

 500,000. 



White Blood Corpuscles or Leucocytes. — The other cor- 

 puscles of the blood, known as white corpuscles, or leucocytes, 

 because they do not contain a color pigment, are larger than 

 the red corpuscles and are characterized further by possessing 

 a nucleus. They are not as numerous as the erythrocytes, 

 varying from 5000 to 10,000 per cubic millimeter. This 

 number varies still more widely under certain pathological 

 conditions. The functions of the leucocytes is not fully estab- 

 lished. They have been termed blood scavengers, as it is claimed 

 that they destroy pathogenic organisms such as bacteria, 

 either by devouring them, or by producing other substances 



