254 
Journal of Agricultural Research 
Vol. XXVII, No. 5 
PRESENTATION AND DISCUSSION OF EXPERIMENTAL DATA 
The results secured in the investigation group themselves under two 
heads: Effect of the sodium hydroxid on the composition of the hulls; 
effect on the digestibility and feeding value of the hulls. 
EFFECT OF SODIUM HYDROXID ON THE COMPOSITION OF THE HULLS 
This group of results can be subdivided into four distinct topics, 
which follow: 
LOSSES IN WEIGHT IN THE TREATED MATERIALS DUE TO THE ACTION OR THE SODIUM 
HYDROXID, AND REDUCTION IN THE STRENGTH OF THE SODIUM HYDROXID 
The loss in weight was ascertained on a dry-matter basis by weighing 
the material and making dry-matter determinations, both before and after 
treatment. The reduction in strength of the soda was determined by 
titration with N/2 sulphuric acid. The following table sets forth the 
figures : 
Table I .—Loss in weight on treatment with soda and reduction in strength of soda. 
Material. 
Loss in 
weight on 
treatment 
(dry-mat¬ 
ter basis). 
Strength 
of NaOH 
employed. 
Strength 
of NaOH 
after use. 
NaOH 
con¬ 
sumed. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Oat hulls. 
16.54 
i- 5 
O. 70 
53 - 33 
Do. 
10.74 
1 
.46 
54.00 
Barley hulls. 
20. 29 
i -5 
I. 04 
30. 66 
Do. 
I 9 - 3 I 
1 
.64 
36.00 
Rice hulls. 
15. 60 
i -5 
• 75 
50. 00 
Do. 
19 - 51 
3 
2. 28 
24. 00 
Cottonseed hulls. 
9. 69 
i -5 
• 75 
50. 00 
Flax shives. 
2 5-03 
i -5 
1 
.80 
46. 66 
These losses are due, as already explained, to solution and separation 
of the silicic acid, a portion of the lignin, more or less of the cellulose 
and pentosans, and to unavoidable mechanical loss. In draining off the 
soda liquor and subsequent wash water, more or less of the fine particles 
of the treated hulls passed through the finest sieve that it was prac¬ 
ticable to use. This was especially true of the flax shives, as they were 
ground quite fine when received. The mechanical loss, however, is 
believed to have been small. 
The average loss in weight for the several substances when 1.5 per 
cent NaOH was used was equivalent to 17.43 per cent °f th e original 
material; when 1 per cent NaOH was used the average loss was slightly 
less—15.03 per cent; and in the single instance where 3 per cent NaOH 
was employed the loss was slightly higher—19.5 per cent; indicating that 
the stronger the soda solution the greater the loss, and that for a given 
strength of soda the loss depended upon the character of the material 
treated. 
The reduction in strength of the sodium hydroxid is due to neutral¬ 
ization by the acetic acid formed. In this connection it may be 
worth while to record our observation of what took place when the 
hulls were added to the NaOH solution in the tank. During the first 
