METHODS OF COCOA ANALYSES. 949 



For the preparation of the sample for microscopical examination, a 

 convenient portion is washed with ether by decantation in a small test 

 tube ; when the ether has evaporated from the residue, a portion is 

 triturated in a small mortar with a small quantity of solution of chlori- 

 nated soda until nearly or just decolorized ; the mixture is then washed 

 into a large test tube, or conical glass, diluted with much water, and 

 set aside to settle. The sediment thus obtained is removed with a 

 pipette for the microscopical examination. If both color and form are 

 found necessary for the identification of any structures, the reserved 

 portion of unbleached and fat-free material is used for this purpose. 



A knowledge of the structures of the spices used for flavoring cocoa 

 preparations, sufficiently accurate to enable one to readily distinguish 

 them from substances added as adulterants, is very important; to 

 identify the individual spices when several have been used in the same 

 preparation is a very difficult and generally a highly unimportant prob- 

 lem. The ordinary flavoring materials are vanilla and cinnamon ; cloves, 

 nutmeg, mace, cardamom, Peruvian balsam, and artificial vanillin are 

 also reported as flavoring materials. 



Starch, flour, and husks are the more ordinary adulterants to be 

 detected with the microscope ; Moeller } reports the materials most 

 commonly used to be wheat and potato starches, next rice and arrow- 

 root, and finally wheat, acorn, and rye flours, ground peanuts, and in 

 malted preparations raw malt as a substitute for malt extract; to these 

 Mace 2 adds almond cake and sawdust. As the collecting of valueless 

 waste products and the converting them into suitable materials for the 

 adulteration of commodities of value has become a well-established 

 industry, every investigator must be prepared to find many new sub- 

 stances used for this purpose, and must not be disappointed if he finds 

 none of those that have recently been reported. To know what to 

 expect to find, he should consider the current prices, abundance, and 

 suitability of available materials, as well as the results of previous 

 investigations. 



METHODS OF ANALYSIS REPORTED BY VARIOUS CHEMISTS. 



A brief review of the methods that have been used or recommended 

 for the analysis of cocoa and its preparation is here given. If any im- 

 portant recently reported methods have been omitted, it is due to a 

 greatly regretted and unintentional oversight. 



Preparation of the sample. The method of analysis adopted by the Association of 

 Swiss Analytical Chemists 3 directs that the substance should always be finely pow- 

 dered or rasped, and kept in well-stoppered bottles. Bensemann 4 prepares the 

 beans by grinding in a porcelain mortar, separates the husk by use of a knife, and 



1 Op. cit., note 3, p. 940 of this work. 



2 Mace", Les substances alimeutaires 6tudi6es au microscope. 



3 Vierteljahresschrift ii. d. Fortschritte auf d. Gebiete d. Chem. d. Nahr. u. Genusa- 

 mittel, 1890, 2, 171. 



< Rep. f. anal. Chem., 1884, 4, 213. 



