278 THE POTATO 



The protein content is low and the carbohydrates 

 high, and, therefore, potatoes are especially valu- 

 able for use in connection with foods rich in pro- 

 tein, such as lean meat, eggs, etc., to furnish a 

 well-balanced diet. The subject of the starch 

 content of potatoes is thus seen to be one of great 

 importance, and during recent years it has at- 

 tracted increased attention from American and 

 European investigators. 



"An interesting study of the conditions affect- 

 ing the starch content of potatoes, begun in 1889, 

 is reported in the Annual Report of the Wisconsin 

 Experiment Station for 1895. In these investi- 

 gations the starch content was approximately 

 determined by means of the specific gravity of the 

 tubers. Since by far the greater .part of the -po- 

 tato tuber is starch and water, and since starch is 

 heavier fhan water, it is evident that the variation 

 in starch content will affect the specific gravity 

 of the tuber. 



"Among the forty-six varieties of the crop of 

 1889 the variety Zenith showed the highest starch 

 content, 22.9 per cent., and Rural Blush the least, 

 13.1, the average for all varieties being 16.2 per 

 cent. In 1890 thirty-one varieties, mostly dif- 

 ferent from those tested the year previous, had an 

 average starch content of 14.3 per cent., Burbank 

 showing the highest, 17.7, and the Kidney, a po- 

 tato from Germany, the least, 11.4 per cent. All 

 these varieties of potatoes were grown on the 

 same kind of soil and under practically the same 

 cultural conditions. Still, the variation in starch 

 content was as much as 9.8 per cent. 



"The starch content was found to vary with 

 the season with different tubers of the same va- 

 riety. Pronged and regular tubers of four varieties 



