90 THE POTATO 



"Of all the common root crops, the potatoes, 

 including the yam and the sweet potato, are the 

 most valuable for the production of alcohol, mean- 

 ing by this term that they contain more ferment- 

 able matter for 100 pounds than other root crops. 

 This is shown by the following comparative 

 statement: 



White turnips 6 to 8 per cent. 



Rutabagas 8 " 13 



Mangel-wurzels 8 " 15 



Carrots 8 " 16 



Parsnips 8 " 17 



Sugar-beets 10 " 22 



Potatoes, sweet potatoes and yams . 14 " 26 " " 



"Under the most favorable circumstances and 

 with potatoes which have been bred especially for 

 the purpose an average content of fermentable 

 matter of about 20 per cent, may be reasonably 

 expected. It is thus seen that approximately 

 ten pounds of industrial alcohol can be made 

 from one hundred pounds of potatoes. If sixty 

 pounds be taken as the average weight of a bushel 

 of potatoes, there are found therein twelve pounds 

 of fermentable matter, from which six pounds of 

 industrial alcohol can be produced, or six sevenths 

 of a gallon. It has also been shown that at the 

 prices quoted in 1905 the amount of Indian corn 

 necessary for the production of a gallon of indus- 

 trial alcohol costs not less than 15 cents. From 

 this it is evident that the potatoes for alcohol mak- 

 ing will have to be produced at a cost not to exceed 

 15 cents per bushel before they can compete with 

 Indian corn for the manufacture of industrial 

 alcohol. 



"The three principal steps in the manufacture of 



