240 DISTURBANCES OF CIRCULATION 



phoric acid are almost entirely absent. Another important fact is that 

 when the plasma is combusted, the acid radicals remaining do not suffice 

 to balance the bases, indicating that much of the inorganic bases is 

 joined with organic substances, probably as ion-proteid compounds. 

 The alkali joined to the proteid is non-diffusible, and constitutes about 

 five-sixths of the total alkali. 



The concentration of the electrolytes of the blood has been deter- 

 mined by ascertaining the lowering of the freezing-point, which in 

 human blood averages about 0.526; this corresponds closely to the effect 

 of a salt solution of 0. 9 per cent, strength. About three- fourths of the 

 dissolved molecules of the blood-serum are electrolytes, and about three- 

 fourths of these are molecules of NaCl, most of which are in the dis- 

 sociated state. 1 



Enzymes. A large number of enzymes exist in the blood, the follow- 

 ing having been detected : diastase, glucase, lipase, thrombin, rennin, and 

 proteases. The proteases are held in check to a large extent by " anti- 

 ferments" that are also present (see "Enzymes," p. 72). In relation to 

 the antiferments are the innumerable antibodies that exist normally in 

 the serUm for foreign proteids, foreign cells, and for bacteria and their 

 toxins, as well as those resulting from reaction to infection, etc. 



The proportions in which the constituents of the plasma normally occur 

 have been determined by Hoppe-Seyler and by Hammarsten as follows : 2 



TABLE I. 



No. 1. No. 2. 



Water 908.4 917.6 



Solids 91.6 82.4 



Total proteids 77.6 69.5 



Fibrin 10.1 6.5 



Globulin 



Seralbumin 24.6 



Fat 1.2] 



Extractive substances 4.0 I -ion 



Soluble salts 6.4 [ 



Insoluble salts 1-7 J 



No. 1 is an analysis by Hoppe-Seyler. 



No. 2 is the average of three analyses made by Hammarsten. 



Alkalescence. It is very difficult to determine the exact 

 alkalinity of the blood plasma. If we titrate with an acid, we 

 liberate much of the alkali from the proteids, dissociate all the 

 Na 2 CO 3 present, as well as the NaHCO 3 and the sodium phos- 

 phate, and find in this way that the entire fresh blood contains 

 neutralizable alkali corresponding to a solution of Na 2 CO 3 of 

 about 0.443 per cent, strength (Strauss). In other words, the 

 blood has a quantity of alkali in combination that can be drawn 



1 Concerning relation of conductivity to freezing-point see Wilson, Amer. 

 Jour, of Physiol., 1906 (16), 438. 



Concerning the viscosity of the blood see Burton-Opitz, Pfl tiger's Arch., 1906 

 (112), 189; and Determann, Zeit. klin. Med., 1906 (59), H. 2-4. 



2 For complete analyses of the blood see Abderhalden, Zeit. physiol. Chem., 

 1898 (25), 106. 



