450 



VICTOK C. MYEES 



Mineral Constituents 



Sodium. Comparatively few figures are available for the sodium con- 

 tent of blood. Macallum gives the normal range of figures for normal 

 human plasma as 220 to 316 mg. per 100 c.c., while more recently Kramer 

 has found in adults and children 280 to 310 m^f. per 100 c.c. of serum. 

 Greenwald has obtained quite similar figures for dog serum. It has 

 long been recognized that sodium was found chiefly in the body fluids, 

 while potassium was a constituent principally of the cellular tissue. As 

 might be expected, therefore, sodium is found chiefly in the blood plasma, 

 and potassium in the corpuscles. Nothing of special importance is known 

 regarding pathological variations in the sodium content of the blood. 



Potassium. Although the information available at present concern- 

 ing the potassium content of blood is somewhat limited, considerably 

 more is known than in the case of sodium. Some years ago Abderhalden 

 reported analyses of the blood of different animals. The figures obtained 

 for potassium are of considerable interest. In the dog and cat practically 

 identical figures were found for the serum and whole blood. This amount- 

 ed to about 22 mg. per 100 c.c., which is almost the exact amount found 

 in the serum of the various animals examined. In the ox^ sheep and goat 

 the figures for the whole blood were about one and one-half times that 

 of the serum, while in the horse, pig and rabbit the potassium concentra- 

 tion of the whole blood was about ten times that of the serum. 



The potassium content of human blood has recently been considered 

 by Macallum (c), Greenwald (A), Kramer, and Myers and Short, who are 

 in close agreement that the potassium of normal human blood serum or 

 plasma is a relatively constant quantity and amounts to close to 20 mg. K 

 per 100 c.c. Kramer has suggested a normal range of 16 to 22 mg. to 

 100 c.c. The potassium content of whole blood depends in large measure 

 upon the cell content, but appears to vary somewhere between 150 and 

 250 mg. to 100 c.c. in the normal human subject. In primary and second- 

 ary anemia the amount may obviously be very low. Pathologically, the 

 potassium content of the serum or plasma is of greater interest. It has 

 been suggested by Smillie that uremic symptoms may be due in some 

 instances to potassium poisoning, while Macallum has obtained some data 

 which suggest an increased potassium content of the serum in eclampsia. 

 The data so far reported on pathological cases are too limited to permit 

 any definite conclusions with regard to the findings. The observations of 

 Myers and Short make improbable a definite potassium retention in 

 chronic nephritis with marked nitrogen retention. 



Calcium. As has been shown by Abderhalden and others, the blood 

 corpuscles are very low in their content of calcium. This being the case 

 significant changes in the blood calcium are best shown, as pointed out 



