Weender’s process[73] as worked out by Henneberg is the one usually adopted for the determination of crude fibre in plants, although recently H. Suringar, B. Tollens[74] and more particular König[75] have pointed out that in Weender’s process the so-called pentosan, that is to say, the sugar-like constituent of the composition C_{5}H_{10}O_{5}, which comprises a not inconsiderable portion of the crude fibre, undergoes a disproportionate alteration, so that the analytical results thus obtained can by no means give an accurate representation of the amount of cellulose. The crude fibre must therefore be treated in such manner as to eliminate the pentosan. For this purpose the various methods of König, Matthes and Streitberger have been proposed, to which we shall return in Book 4. Filsinger, the meritorious experimenter on the subject of cacao, has by König’s method determined the amount of crude fibre in a series of different varieties of cacao bean, and obtained the following results as regards shelled and roasted beans. percent 1. Puerto Cabello 5·37 2. Java 3·97 3. Ariba Guayaquil I 4·10 4. Ariba Guayaquil II 4·07 5. Machala Guayaquil I 4·43 6. Para 4·01 7. Surinam Guiana 3·01 8. Bahia 2·81 9. Grenada 3·10 10. Guatemala 3·50 11. Machala Guayaquil II 3·58 12. Caracas 3·65 13. Samana 4·58 14. St. Thomé A I 4·13 15. St. Thomé A II 2·95 16. St. Thomé B 3·15 17. Haiti 3·12[76] These new values may be provisionally regarded as normal. From these results not only can an idea of the functioning of the cacao shelling machine be obtained, but also the presence of any occasional admixture of husk in cacao preparations may be inferred, since the husk contains a great deal more crude fibre than the kernel. Therefore the determination of the crude fibre is an important item in the testing of cacao preparations, as there is no doubt that the presence of vegetable substances rich in crude fibre can be detected by the increase in the amount of cellulose. 8. ~Sugar and plant acids.~ The presence of glucose in raw cacao beans was first pointed out by Schweitzer[77]. The sugar is formed by the action of the cacao ferment on the glucoside cacaonin during the processes of drying and fermentation. In addition to sugar, malic and tartaric acids have been observed. These substances, however, are only of interest to the plant physiologist and not to the manufacturer, so it is sufficient merely to notice them here in passing. 9. ~The mineral or ash constituents.~