[152] Berichte der Deutschen Chemischen Gesellschaft Vol. VII, p. 698 and Friedländer, Fortsch. der Theefarbenfabrikation, Berlin 1888, p. 583 and elsewhere. [153] L’état actuel de l’industrie de la parfumerie en France. Revue Générale des sciences pures et appliquées, Paris 1897, p. 663. [154] Chem. Zeit. Repert. 1898, p. 181. [155] Pharm. Zeit. 1888, p. 634 and Pharm. Centralhalle 1898, p. 673. [156] Zeitschr. für angewandte Chemie 1899, p. 428. [157] Pharmaceutische Centralhalle 1898, p. 357. [158] Berlin 1899, Jul. Sprenger, page 53 et seq. [159] K. Dieterich, Die Analyse der Harze, Balsame und Gummiharze, Berlin 1900, page 76. [160] Regulation of 22 and January 1896. [161] See also Farbenzeitung 1909, vol. XV, pages 301, 348, 392 and 436. +Part IV.+ Examination and Analysis of Cacao Preparations. A. Chemical and microscopical examination of cacao and cacao preparations. The following observations will serve as an introduction to the chemical and microscopical examination of cacao preparations calculated to be of special value to the food chemist, corresponding as they do to the state of scientific progress at the present day and special attention being paid to the critical treatment of the methods of analysis etc. adopted. a) Testing. This is a point of great importance, inasmuch as it directly influences the result of the analysis of cacao goods. This is especially the case when dealing with ~cocoa powders~, as the test is liable to vary considerably according to the amount of moisture contained in the preparation and the degree of fineness of the powder. In the case of cocoa powders, the sample should be taken repeatedly from a large supply, and from all parts of the material to ensure getting an average sample. The samples taken should be of uniform volume and should, before proceeding to apply the test, be closely mixed together, being, if possible, first passed through a fine sieve. The material ready for the following experiments should then be placed in tin, or better still, glass receptacles with well-fitting corks or stoppers. Paper wrappings or cardboard-boxes are not to be recommended, as the powder is apt to become drier or moister according to the state of the atmosphere to which the packets are exposed. The most suitable quantity for experimental purposes is, in the case of both chocolate and cocoa powder, as well as butter and covering material, 100 kilogrammes. When determining the amount of foreign fat in cacao preparations, however, as well as estimating the ash content of powder, up to 250 kilogrammes of sample material can be used. In Germany the regulations of the Commercial Agencies of the government public food chemists obtain when sampling and analysing cacao preparations.[162] b) Chemical Analyses.