BLOOD AND LYMPH 251 



diabetes, arteriosclerosis, and syphilis. (See page 291 for quantitative 

 method.) 



Uric acid is present in normal blood to the extent of about 2-3 mg. 

 per 100 c.c. of blood. In gout this value may be increased to 4-10 mg. 

 The quantitative determination of the uric acid content of blood is of 

 importance as an aid in differentiating gout and certain other disorders 

 exhibiting similar clinical symptoms (for methods see page 281). 



The non-protein nitrogen of normal blood amounts to about 25-30 

 mg. per 100 c.c. of blood. The urea forms about 50 per cent of this, 

 creatinine 2 per cent, uric acid 2 per cent, ammonia 0.3 per cent, and 

 amino-acids, etc., about 46 per cent. In nephritis the non-protein 

 nitrogen of the blood is much increased. In the laboratories of Jeffer- 

 son Medical College analysis of the blood in a fatal case of uremia 

 showed a non-protein nitrogen value above 46*0 mg. l 



Amino-acids are always present in the blood. They result for the 

 most part from the digestion of protein material in the intestine. 



Creatinine occurs in normal blood to the extent of about 1-2 mg. 

 per 100 c.c. of blood. In uremia the amount is increased. 8 Various 

 investigators report the values as ranging from 4 to 35 mg. per 100 c.c. 



The creatine content of normal blood averages about 3 mg. per 

 100 c.c. of blood. The creatine values have no important pathological 

 significance as far as known at the present time. 



The acetone (acetone and acetoacetic acid) content of normal blood 

 ranges from o to i mg. per 100 c.c. of blood. In mild diabetes mellitus 

 the value rises to 5-12 mg., whereas in severe diabetes mellitus (coma) 

 as much as 20-45 m - P er IO c - c - f blood serum has been found. 



Normal blood contains about 20 per cent of solids and 3 per cent of 

 total nitrogen, whereas chlorides are present to the extent of about 0.50 

 per cent. In severe diabetes the chlorides are decreased because of the 

 accompanying diuresis. 



Abel 3 and associates have devised a method by which diffusible 

 substances may be removed from the blood of a living animal. The 

 process is termed vividiffusion and is brought about by permitting the 

 blood from an artery to flow through collodion tubes surrounded by 

 physiological salt solution. The dialyzable substances, except sodium 

 chloride, are removed and the dialyzed blood is returned to the body of 

 the animal by means of a vein. The apparatus has been modified by 

 McGuigan and von Hess. 4 



1 Weiss and Hamilton: Reported before College of Physicians, Philadelphia May, 1921, 

 unpublished. 



J Folin and Denis: Jour. Biol. Chem., 17, 487, 1914. 

 Myers and Fine: Jour. Biol. Chem., 20, 391, 1915. 



3 Abel, Rowntree and Turner: Transactions of the Ass'n of American Physicians, 1913; 

 also Jour, of P harm, and Exp. Therap., 5, 275, 1914. 



4 McGuigan and Von Hess: Jour. Pharm. and Exp. Therap., vol. 6, 1914, 



