Alfred Michel of Eilenberg[100] utilises the shells in the preparation of a brown colouring material. The husks, free from impurities, are first soaked in soft water, with or without the addition of sulphuric acid, then washed and finally treated with a strong 35 % solution of caustic soda. From the alkaline solution, the colouring matter is precipitated with acid or acid metallic salt, collected on a filter, and again washed. Thus obtained, it is a dark reddish-brown paste, possessed of a vitreous fracture. The yield of colouring matter is from 20-25 % of the weight of the original shells. By re-treatment with alkali, the paste can be again obtained in solution and can be used as required, either in liquid or paste form. The colouring matter can be obtained in different tints, either by soaking the shells in more er less dilute sulphuric acid, or by precipitation from the alkaline solution at various temperatures, or yet again, by the addition of metallic oxides. Boussignault[101] says that in Paris briquettes have been made from cacao shells, and twenty-two years ago, Zipperer[102] proposed to use them as fodder, especially for horses. Experimental work in that direction was instituted, but for various reasons, had to be abandoned. The question as to a rational working up of the husk of the cacao bean is once more receiving special consideration, more particularly since the publication by the “Association of German Chocolate Manufacturers” of a prize essay on the subject. The fodder value of the husks as determined by Märcker is apparent from the following figures: ~Table~ 18. ===========================+=============+===========+=========== | free from | | whole and Shells | dust, whole | fine meal | dusty | % | % | % ===========================+=============+===========+=========== Moisture | 9·08 | 6·50 | 9·95 Albumen | 13·56 | 14·13 | 12·69 “ digestible | 6·06 | 7·07 | 4·38 Fat | 2·65 | 6·76 | 3·96 Raw fibre | 29·14 | 25·80 | 21·55 Ash | 6·32 | 6·44 | 7·26 Non-nitrogenous extractive | 39·25 | 40·37 | 44·59 Feeding experiments which were carried out in certain agricultural institutes showed that the cacao husk stands in nutritive value between good meadow hay and wheaten bran, and is not only a fattening fodder for oxen, but also a valuable feeding material for cows and deer[103]. These results have been confirmed by Prof. Feruccio Faelli in Turin[104].