4 COMPOSITION OF GREEN RYE AND RAPE. 



employed in the determination of the various constituents enter- 

 ing into the composition of these two crops. 



1. Determination of water and ash. For the determination of 

 water 1000 grs. of the fresh substance were taken. The weighed 

 substance was first dried in the air, subsequently at the top of a 

 water-bath, and finally in a hot-air bath, at a temperature of 

 220 Fahr. 



The loss in weight, by calculation, gave the per-centage of 

 water. 



Two separate portions of the dried substance were then re- 

 duced to ash, at a moderate heat, over a gas-burner, in a platinum 

 capsule. 



2. Determination of cellular fibre, insoluble protein compounds ^ 

 and insoluble inorganic salts attached to the fibre. The separation 

 of all the soluble constituents from the insoluble was effected in 

 the following manner : 



For analysis 1000 grs. of the fresh rye or rape were weighed 

 out at the same time at which the respective portions for the 

 water-determination were weighed. I am particular in stating 

 this, because the amount of water in the leaves and other parts of 

 green plants varies from day to day, for which reason the weigh- 

 ings for the different determinations ought to be made all at the 

 same time. In order to secure a fair average sample, it is ad- 

 visable to cut the fresh plant, or that part of the plant which is to 

 be analysed, in one or two-inch pieces, and to mix together a 

 quantity of such bits, sufficient for all the separate determinations. 

 If this precaution is neglected, on adding up the results of the 

 analyses there will be found almost always either an excess or a 

 deficiency. 



The 1000 grs. of the fresh substance were mashed in a porcelain 

 mortar to a fine pulp, with the addition of a small quantity of 

 distilled water. The preparation of a fine pulp, in the case of 

 grass or leaves, is a tedious process, which succeeds best by using 

 no more water than is necessary to prevent portions of the sub- 

 stance being thrown out of the mortar by agitation with the 

 pestle. When sufficiently fine, about four or five ounces of 

 distilled water were added, and the pulp digested with it for about 

 half an hour. After that time the liquid, containing in solution 

 gum, sugar, soluble albumen, and other soluble matters, was 

 strained through a piece of fine linen, previously wetted with 

 distilled water, and tied over a large glass beaker. The impure 

 cellular fibre on the linen was squeezed in the cloth as tightly 

 as possible, then transferred back in the mortar, and thoroughly 

 agitated with the pestle, a small quantity of water being added at 

 the same time, The insoluble portion was then again digested 

 with four to five ounces of distilled water for half an hour, and the 

 liquid strained through the linen cloth as before. The same opera- 



