950 FOODS AND FOOD ADULTERANTS. 
scrapes chocolate with a knife to prepare it for analysis. Mansfeld! recommends 
that the material be finely rasped or powdered. 
Determination of moisture.—The Association of Swiss Analytical Chemists? makes this 
determination in cocoa powder. Two grams are spread in a thin layer on a watch 
glass and dried to constant weight at 105° C. Bensemann?® dries 2 grams to a con- 
stant weight at 100° C.; Herbst, a weighed quantity, mixed with twice its weight 
of sand, at 60° to 80° C.; Mansfeld,! 5 grams to constant weight at 100°C. 
Quantitative and qualitative examination of the ash.—For quantitative determination, 
the method of the Association Swiss Analytical Chemists 2 directs that the material 
be incinerated in a platinum dish, carefully burned at a low red heat until the ash 
is white, and after moistening with (NH,).COs, gently reignited. The ash is also 
examined qualitatively for mineral substances and pigments; as ocher, bolus, excess 
of alkaline carbonates used in making the cocoa soluble, ete. 
Bensemann.*—Two grams of material are carbonized, extracted with water, and 
the residue washed and incinerated. The aqueous extract isadded to theash and the 
whole evaporated todryness. Theresidueis dried at 100° C., weighed, and the result 
taken as ash. All ashes were of a light gray, almost white, color, so that the addi- 
tion of ocher, bolus, etc., could be easily detected by a red color of the ash. 
Mansfeld! burns 5 grams at a low temperature and tests the ash for mineral addi- 
tions; as ocher, excess of alkaline carbonates, ete. 
Stutzer® mixes 2 grams with sand, incinerates at a moderate heat, adds NH, NOs, 
and ignites again until the ash is white and free from CO, and nitrates. In a recent 
article® this writer has called attention to the value of the additional determinations 
of ash soluble in water, total P.O; and P.O; soluble in water, as a means of detect- 
ing the use of fixed alkalis and ammonia in the process of manufacture. His results 
are given in the table on page 943. 
Quantitatived etermination of fat.—Association of Swiss Analytical Chemists.2—The 
sample is mixed with sand, extracted with absolute ether in a Soxhlet apparatus for 
six to eight hours; the ether is removed by careful evaporation, and the fat dried at 
100° C. 
Bensemann.*—Two grams of the substance are rubbed to a powder in a mortar 
warmed to 60° C., some gypsum being added to facilitate the pulverizing. The mass 
is extracted with ether in a Soxhlet apparatus and the extract is dried at 100° C. 
Blyth.7—The best method of extracting the fatis to exhaust the nibs with ether in 
a Soxhlet apparatus. 
Boussingault.* mixes the material with sand and extracts with carbon disulphide. 
Hassall..—Three grams of cocoa are dried in the water bath and exhausted with 
ether; the ether is evaporated off, and the residue dried and weighed. This residue 
contains some or all of the theobromine, the amount of which must be determined 
and subtracted from the ether extract. 
Herbst.t—The residue from the moisture determination is extracted with ether and 
the extract dried at 100° C. 
1 Zeitschr. d. allgem. 6sterr. Apotek. Ver., 44, 329. 
2 Vierteljahresschrift ti. d. Fortschritte auf d. Gebiete d. Chem. d. Nahr. u. Genus- 
smittel, 1890, 2, 171. 
3 Rep. f. anal. Chem., 1884, 4, 213. 
4Rundschau, 1882, 443; Rep. d. anal. Chem., 2, 236; Zeitsch. f. anal. Chem., 22, 278. 
5Rep. f. anal. Chem., 1882, 88 and 165; Hygiene-Bericht, 1882-3, 1, 217. 
‘Op. cit., note 3, p. 939 of this work. 
7 Op. cit., note 3, p. 936 of this work. 
8 Ann. Chem. Phys., [5], 28, 433; Jour. Chem. Soc., 1884, 46, 202; Chem. Ztg., 1883, 
203, and 902. 
9 Op. cit., note 2, p. 940 of this work, 
ee Te ee es ee ee ee ee ee ee 
4 
