CHAPTER XX. 

 ALCOHOL. 



Fermentation. The juice of the apple as it is found in 

 the fruit is healthful. If the juice is pressed out of the 

 fruit and set in a warm place, it will soon be observed that 

 bubbles of gas are given off. From this we may know 

 that a sharp, pungent liquid is forming in the juice. The 

 gas is carbon dioxid, and the new liquid is alcohol. 

 Pressed-out fruit juices undergoing this change usually 

 become frothy, or "work," as we say, and at the same 

 time acquire a sharp taste. This change is due to a 

 process called fermentation. 



Any substance in which alcohol is produced in this way 

 is found to contain a microscopic, one-celled plant, oval or 

 elliptical in outline, which acts as a ferment. These fer- 

 ments are found on the skins and stems of fruit as it is 

 ripening, and there they do no harm ; but when the fruit 

 is crushed and the juice pressed out, these ferments are 

 washed into the juice, and as has been clearly proved, are 

 the causes of the changes in the fruit juice described above. 

 In the liquid they begin to grow and multiply, and as they 

 grow they break up or decompose the sugar of the juice, 

 and form at least two substances, carbon dioxid and alcohol. 

 This change is called alcoholic fermentation. 



A small number of ferments can change a large amount 

 of the sugar of a fruit juice into carbon dioxid and alcohol. 

 The juice of sweet apples contains much sugar, and thus 



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