CHAPTER XVIII 



COLLOID STATES AND PHYSIOLOGICAL DIVISION OF 



LABOUR 



WE have been making great use of the expression " colloid 

 state," and we are unable to define it. At least, in the 

 present state of science, we cannot describe the arrange- 

 ment of particles and solvent in a given colloid, nor the 

 electric state of the parts, nor establish by figures the 

 characteristics of any particular colloid state. In other 

 words, we cannot make an artificial analysis of a given 

 colloid to satisfy the human mind. But on the other hand 

 and this precisely is the natural method of biological 

 studies we can characterize a colloid with reference to 

 another colloid. 



We recognize a colloid by its origin and its effects. For 

 us it is defined by the function (A x B), in which A and 

 B are known. For example, we defined sucrase by the 

 function (Yeast x Saccharose) or (Aspergillus x Saccharose), 

 and w^e recognize it by its inverting cane sugar. Perhaps 

 even we are wrong in saying Sucrase simply, defining it by 

 its effect, for it is probable that the Sucrase of yeast is 

 different from the Sucrase of Aspergillus. When the colloid 

 is a toxin we have a contrary tendency to define it solely 

 by its origin and to say, for example, " tetanic toxin," 

 whereas the function (Tetanus x Sheep) is perhaps different 

 from the function (Tetanus x Guinea-pig). 



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