CHEMICAL PHYSIOLOGY. 23 



fatty acid radical. 1 Tributyrine, a fat occurring in 

 butter, has this formula : 



3 monodynamic atoms of butyryl = (C^H^O) 1 



(C 4 H 7 0)< L 



1 tridynamic atom of glyceryl = (C 3 H 5 ) ni ^ 



held together by three didynamic atoms of typical 

 oxygen. 



The Roman numeral to the right of the radical buty- 

 ryl signifies that it is a monodynamic radical, and can 

 replace only one atom of hydrogen ; but the Roman 

 numeral to the right of glyceryl shows it to be a tri- 

 dynamic radical, which by its one atom replaces three 

 atoms of hydrogen. 



The other fats occurring in the human body and in 

 animal food are tripalmitine 



3(C 16 H 81 0) 

 (C 3 H 6 )'" 



which is equal to the large formula of 



jo, 



tristearine, a fat abounding in mutton and beef, of the 

 formula 



CsyHnoOg 



and trieleine, a more fluid fat, which abounds in the 

 oils extracted from lower animals and vegetable seeds. 



Yellow animal fats contain luteine, a yellow coloured 

 substance showing peculiar absorption phenomena 

 (three bands) in the blue part of the solar spectrum. 



When these fats have passed through the stomach, 



