SPICES. 



163 



material in a 000 cc flask with 1 gram of copper sulphate, 1 grain of mercuric 

 oxid, from in to IS grams of potassium sulphate, and 25 cc of sulphuric acid. 

 A HIM- luMtiiiLT gently until frothing ceases, boll the mixture for two to four 

 hours. When nearly cool add about 300 cc of water, 50 cc of 4 per cent 

 potassium sulphid solution, and sodium hydroxid solution to alkaline reaction. 

 Distil into standard acid and titrate with standard alkali, as usual. 



8. Nitrogen in Nonvolatile Ether Extract Winton, Ogden, and Mitchell 



Method. 



(For black and white pepper.) 



Extract 10 grams of pepper for twenty hours in continuous extraction appara- 

 tus with absolute ether, collecting the extract in a weighed flask of about 250 cc 

 rapacity. Kvaporate the ether, dry first, at 100 C., and finally to constant 

 weight at 110 C. Determine the nitrogen in the weighed extract by the 

 rimming- Arnold method, digesting in the same flask used for the extraction. 

 Calculate the parts of nitrogen in 100 parts of nonvolatile ether extract. Black 

 pepper, owing to the presence of piperine, contains not less than 3.25 parts, and 

 white pepper not less than 4 parts, of nitrogen. Linseed meal and other oily 

 adulterants may contain about the same amount of ether extract as pepper, but 

 tliis extract is practically free from nitrogen. 



If desired, crude piperine may be calculated from the nitrogen by multiplying 

 by 20.36. 



9. Ether Extract, Volatile and Nonvolatile^ 



Extract 2 grams of the ground material for twenty hours in a continuous ex- 

 traction apparatus with absolute ether. Transfer the ethereal solution to a 

 tared capsule and allow to evaporate at room temperature. Let stand for eight- 

 een hours over sulphuric acid, and weigh the total ether extract. Heat the ex- 

 tract gradually and then at 110 C. until the weight becomes constant. The loss 

 is volatile oil ; the residue, nonvolatile ether extract. 



10. Alcohol Extract." 



Place 2 grams of material in a 100 cc flask and fill to the mark with 95 per 

 cent alcohol by volume. Stopper, shake at intervals of thirty minutes for eight 

 hours, and allow to stand for sixteen additional hours without shaking. Filter 

 the extract through a dry filter, evaporate 50 cc to dryness in a flat-bottomed 

 dish on a water-bath, and heat to constant weight at 110 C. 



11. Copper Reducing Matters by Direct Inversion Calculated as Starch. 



Extract 4 grams of the sample on a filter that will completely retain the 

 smallest starch granules, with five successive portions of 10 cc of ether. After 

 the ether has evaporated wash with 150 cc of 10 per cent (by volume) alcohol. 



Since it is not possible to wash samples of Batavia cassia with water or dilute 

 I alcohol, owing to the formation of a glutinous mass which clogs the filter, for 

 the sake of uniformity all preliminary washing is best omitted in determinations 

 l made on all varieties of cassia, as well as on cassia buds and cinnamon. 



Carefully wash the residue from the paper into a 500 cc flask with 200 cc of 



8 Richardson, U. S. Dept. Agr., Division of Chemistry, Bui. 13, Part 2, p. 165. 

 "Conn. Agr. Exper. Stat. Kept., 1898, p. 187. 



