THE PHYSIOLOGY OF ALCOHOL. 



597 



incredible power of growth and reproduction. This growth is 

 wholly controlled by external conditions and by the composition 

 of the nutrient medium. Probably no form of life approaches in 

 power of rapid reproduction these minutest plants, the bacteria 

 and yeasts, and none are probably more delicately responsive to 

 varying conditions of life. 



Yeast is able to grow until, by decomposition of sugar, its 

 medium comes to contain fourteen per cent * of common alcohol. 

 At this point, no matter how much sugar and other nutriment 

 remains, further growth is impossible. 



Now, of especial interest to the physiology of nutrition, and 

 the influence upon it of waste products generally, is the question, 



2 00 



lOOO - 



8 00 - 



6 00 



4 00 - 



2 00 - 



0^ NORMAL, 

 /(ooo i. ALCOHOL, 



y 



-*t 



Houf?s 



growth of yeast.. 

 Fig. 1. 



What effect have very minute quantities of alcohol on the growth 

 of yeast ? 



Fig. 1 represents to the eye, in the diagram to the left, the four 

 possible kinds of action in the four lines diverging from the point 

 marked " per cent." If no slowing effect is present until the 

 poison limit, fourteen per cent, is reached, the line marked 

 "normal" should be continued out until directly over a point 

 corresponding to fourteen per cent strength of solution, and then 

 should drop perpendicularly to the zero point of growth on the 

 base line. As a matter of fact, Fliigge states that growth is 

 slowed with twelve per cent and stopped at fourteen per cent. 

 If this be true, instead of dropping vertically, it would fall a 

 little obliquely from twelve per cent to fourteen per cent. This 



* Fliigge, C. Die Mikroorganismen. Leipsic, 1886, p. 482. 



