Physical Chkmistkv and Vktkiunaky Sciknce. 185 



analysis of the colloids of the hlooH, for iiistiiiicc, gives the following 

 result : — 



The blood consists of 



I. MoRPiiOTic Elements — 



(a) Blood plates 



(/)) Leucocytes 



(c) Erythrocytes, red blood cells 



(1) positive colloid = Jifemoglobin 



(2) negative colloids = stroma and membrane 



( + lipoids) 



II. Blood Liquid, Plasma. 



(«) Albumines 



'Colloids which are not sen- 



f 



(1) positive 



(2) negative 



(1) positive albumines | sitive against alterations 



(2) negative albumines I of the concentration of 

 I ions in the solvens 



(h) Globulines 



'These colloids are very sensitive to 

 changes of the concentration of the 

 ions in their medium. Thev are, of 

 course, precipitated by dilution with 

 water or dialysis 



(c) Nucleoproteids (not yet physically analysed) 



The process of coagulation of the plasma is the combination and 

 precipitation of all the negative globulines of the plasma with a part 

 of the positive ones. The arising neutral complex is called ^fibrin 

 (Iscovesco). 



The blood serum therefore contains — 



(1) All the positive and negative albumines. 



(2) Only positive globulines. 



The above-mentioned blood colloids, at present chiefl}' electrically 

 distinguished, also show differences in their thermal behaviour. The 

 mixtures of them in plasma and serum, being in an alkaline medium, 

 have electro-negative character and go to the kathode. 



But the electric character, thermo-stability or lability, precipitati- 

 bility by electrolytes and colloids are not sufficient to explain (besides 

 chemical influences) the functions of the blood colloids in the living 

 organism. There are a number of very fine differences dependent 

 (1) on the proportion of colloid mixtures; (2) on the presence of 

 electrolytes and other crystalloids ; (3) on the concentration, electric 

 charge, \elocity of diffusion and chemical nature of ions ; and (4) on 

 variations of temperature (fever) ; differences in the structure of the 

 colloids which we are not yet able to demonstrate in the test tube 

 except by the so-called biological reaction, but which are sufficient to 

 give the colloid quite another biological behaviour. 



Actually the one best studierl is the complex of biological re- 

 actions of the blood belonging to immunity, the rise of antibodies in 

 the blood and their reactions with the corresponding antigenes. 



