136 EXPERLMENT STATION. [Jan. 



at about 50° C. The roots were secured in November of the 

 second year after setting, when translocation from the tops was 

 believed to be complete. Eor subsequent study of the effects 

 of different fertilizers the individual samples were separately 

 analyzed ; but for this report detailed results are unnecessary. 

 The average proximate comj)osition of the dry matter of IH 

 roots was as follows : — 



Per Cent. 



Protein (nitrogen x 6.25), 11.03 



Fat, 1.00 



Fiber, 15.39 



Nitrogen-free extract, 66.34 



Ash,' 6.24 



The proximate composition showed clearly that the soluble 

 non-nitrogenous matter included most of the reserve material 

 of the roots. 



The methods of the Association of Official Agricultural 

 Chemists - for sugars, starch, pentosans and galactans were em- 

 ployed for estimating the different carbohydrates in the reserve 

 material. 



An examination of 25 roots showed 12 to contain no reducing 

 sugars^ while most of the others had only traces present ; there- 

 fore reducing sugars were not estimated, but were reckoned with 

 total sugars. The latter were especially abundant, and ranged 

 from 26.4 per cent, to 50.8 per cent., only two samples contain- 

 ing less than 35 per cent, calculated to dry matter. 



Pentosans were determined in 16 samples, and ranged from 

 Y.32 per cent, to 10.68 per cent, in the dry matter. Galactans 

 were determined in 4 individual samples and in a composite 

 sample, but were insignificant in amount, averaging only 1.04 

 per cent. 



In the estimation of starch by the diastase method, it was 

 found that there was no more glucose obtained than was account- 

 able from the diastatic extract. Subsequent examination re- 

 vealed starch in only microscopic traces. Six different sam- 

 ples, after having undergone the diastase treatment as for starch, 



• Ash determinations were made in the fertilizer division of the department. 



2 Bulletin No. 107, Bureau of Chemistry, United States Department of Agriculture, pp. 38-56. 



