112 Analysis of Feeding Materials [174, 175 



namely, the analysis of thejuice or soluble portion, and the 

 analysis of the crude fibre or insoluble portion. 



From the sample it is therefore necessary to procure two 

 sub-samples, one of the juice and one of the insoluble matter. 

 These two must be analysed separately, in the same way as the 

 different parts of hay or grass are worked upon. And just as 

 happens in the case of hay, &c, the first thing to be estimated 

 in roots is the moisture, which leads to the following 



Preliminary Treatment 



1 74. Take three or four average-sized roots, and split each 

 with a clean knife into eight pieces. Take one of these pieces 

 from each root. Cut the portions into thin slices, and weigh 

 out about 100 grams of the slices in the rough balance as 

 described in paragraph 158. When weighed spread the slices 

 out on the filter paper, and dry them in the air oven at 6o° C. 

 until they become shrivelled up. The slices will now be hard 

 and fairly brittle. Break them up as finely as can conve- 

 niently be done by hand, and then dry in the steam oven until 

 no further loss in weight takes place. 



This operation takes up three or four days. It will take 

 considerably longer if the oven be allowed to cool during 

 the night, as the partially dried material is very hygroscopic, 

 and absorbs a considerable amount of water whilst the oven is 

 cold. In laboratories where the ovens do not keep hot day 

 and night matters may be considerably hastened by removing 

 the substance from the oven to a desiccator every evening, and 

 returning to the oven as soon as it is warm in the morning. 



175. The moisture, however, is not the only constituent 

 which must be estimated in the fresh root. The two principal 

 portions, as mentioned above, are the crude fibre and the 

 juice. If one of these be estimated, the other may be calcu- 



