16 The Colorado Experiment Station. 
Hants of the hay. This excessive reducng power of the sodic hydrate 
extract of the dung over that of the hay is not an accident or attribu¬ 
table to inaccurate work, for it is uniformly the case with all of the 
dungs corresponding to the six fodders used. 
§37. This result is similar to that obtained for the coefficient 
of digestion for the ether extract in the first series of experiments 
made on the digestion of alfalfa hay in which the amount of ether 
extract obtained from the feces was more than double the amount 
consumed. In this case, I attributed this excess to the solubility of 
fecal matter only after I had canvassed every other apparent ex¬ 
planation, because it was observed in one series of experiments only 
and was not observed in the case of any other fodder than the al¬ 
falfa. If other experimenters have met with such striking results, 
they have rejected them, as I was tempted to do, for the simple rea¬ 
son that others have done this work in the same way and the record¬ 
ed results agreed in showing that my results were, to say the least, 
very exceptional. In this case, however, I have a series of six very 
different fodders and they agree in showing that, in this respect, 
there is a marked difference between the fodders and the feces of the 
animals feeding on them. 
PENTOSANS. 
§38. There are certain complexes existing in the fodders 
which when subjected to distillation with hydrochloric acid yield 
furfurol. In this work, I have considered this furfurol as such and 
have endeavored to determine its coefficients of digestibility for the 
various extracts. 
§39. In Bulletin 39, we found the total amount of furfurol 
calculated as xylan yielded by alfalfa, to range for the first cutting 
from 9.44 to 14.42 per cent.; for the second cutting, hay grown at 
Rocky Ford, 12.34 per cent. The average found for the cutting 
of 1894 was 11.44 per cent.; for 1896, 11.48 and the average for 
all of the determinations made on samples covering the two years 
was 11.48 per cent. 
§40. The furfurol found in the hay used in these experi¬ 
ments, was 8.16 or 13.38 xylan; in the orts 9.95 per cent.; in the 
feces 12.69 per cent, xylan. There were fed 1786.4 grams of xylan. 
The orts contained 98.19 grams and the feces 587.6; accordingly 
1100.6 grams of xylan had been digested or the coefficient of di¬ 
gestion for the total xylan was 65.12. The corresponding amounts 
of furfurol are, in the hay fed 1089.5 grams, in the orts 59.9 grams, 
in the feces 318.9 grams, digestion coefficient 65.18. 
§41. We determined the furfurol in the residue after the 
extraction and not in the evaporated extract for the same reason 
that we determined the extracts themselves by difference, i. e., be- 
