WATER, ITS PROPERTIES AND FUNCTIONS 245 



When dry, both organisms and complex organic compounds, such as enzymes, 

 can withstand, without destruction, a much higher temperature than in the 

 presence of water. 



The molecules of liquids in their movements .past one another experience 

 friction ; this is known as their internal friction and gives rise to their viscosity. 



The part played by the viscosity of the blood in causing the "peripheral 

 resistance " of the arterial system is pointed out, and it is shown that this factor, 

 on which depends, with a given heart beat, the height of the arterial pressure, is 

 due to the internal friction of the blood and not to its friction against the walls 

 of the blood vessels. 



The viscosity of colloidal systems depends, in the main, on the degree of 

 dispersion of the internal phase. In the case of suspensoids, the maximum of 

 viscosity is at a medium degree of dispersion. In the case of emulsoids, where 

 the internal phase is deformable, there are more factors to be taken into account, 

 especially the rate of shear. 



LITERATURE 



General Properties of Water. 



L. J. Henderson (1913, pp. 72-132). 



Constitution. 



Discussion by the Faraday Society, 1910 (Transactions of the Faraday Society, 6, 

 Parti., July 1910). 



Function in Reversible Reactions. 

 Bayliss (1913, 1, pp. 243-244). 



