BLOOD: ITS GENERAL PROPERTIES 89 



variations in the concentration of the proteins. It has been found that 

 the concentration of the blood proteins varies somewhat; during ex- 

 ercise it is increased probably because of the taking up of water by 

 the tissues, and during profuse bleeding it is diminished because 

 large amounts of fluid are being added to the blood from the lymph, 

 which is relatively poor in proteins. The ingestion of considerable 

 amounts of salts has been found to reduce the concentration of the blood 

 proteins for a short time. In pathological conditions, as in diabetes, when 

 rapid changes in the body weight due to alterations in the diet are oc- 

 curring, changes in the fluid content of the blood are often observed. 

 Likewise in edema caused by faulty renal function, there may be a re- 

 tention of fluid in the blood before there is any indication of edema. The 

 hydremic condition of the blood can therefore be considered as a useful 

 diagnostic aid in determining the water metabolism. 



The relative concentration of the proteins of the blood is also of some 

 interest, especially since in certain diseases a considerable amount of 

 blood protein is lost. By refractrometric methods it is possible to sep- 

 arate the globulin and albumin fractions. Normally the total proteins 

 range between 6.7 and 8.7 per cent, of which the albumins lie between 

 4.95 and 7.7 per cent, and the globulins between 1 and 2.54 per cent. In 

 some diseases, as in chronic nephritis, pneumonia, and syphilis, the 

 total proteins of the blood are decreased and the relative amount of 

 serum globulin is increased On the other hand, in many mild infections 

 and chronic septic conditions the globulin fraction may be increased 

 with no change occurring in the total protein content. 3 



Serum Proteins disappear from the blood when the animal is bled and 

 simultaneously transfused with washed corpuscles suspended in saline. 

 If the blood be removed in several moieties during the day, it will be 

 found that 1 per cent of the protein will have reappeared next day, 

 after which it will reappear more slowly taking 5-7 days to return 

 to normal. If the bleeding be performed at one period, however, there 

 will be a very rapid return (within 15 minutes) of a part of it, which 

 indicates the presence of a reserve store of proteins somewhere in the 

 body. A slower regeneration of the remaining part then follows. This 

 regeneration proceeds at about the same rate as that at which the liver 

 regenerates after being damaged by CHC1 3 or P., which suggests a rela- 

 tionship of the liver to the regenerative process of blood proteins. This 

 is further supported by the fact that regeneration of blood proteins is 

 decidedly delayed after the liver has been damaged by P. or CHC1 3 . 

 Further evidence of the relationship of the liver to blood proteins is 

 obtained by the fact that pronounced damage to the liver lowers blood 

 protein somewhat and also that Eck fistula clogs regenerate protein more 



