1896 THE MICROSCOPE. 13 



The Examination of Pepper. — W. Busse, in Mittheilungen 

 der Gesundheitsnmt, states that most of the analytical mf'thods 

 for the valuation of pei^per, such as the deternnnation of the 

 moisture, ethereal oil, mineral matter, alkalies, and })hosphoric 

 acid, are inconclusive, sine-; these constituents are common to 

 the seed and the husk. The value of the cellulose and dextrose 

 estimations must also be called in question. On the other 

 hand, the brown coloring substances are only found in the 

 husk, and their quantitative estimation will show the value of 

 the pepper. To isolate them the following method is proposed : 

 Five grams of the sifted and dried pepper are treated with boil- 

 ing absolute alcohol. The residue, after being freed from alco- 

 hol in the drying oven, is ground up with a little water in a 

 basin, and then washed into a flask with 50 to 60 c.c. of boiling 

 water. Twenty-five c.c. of a 10 per cent solution of soda are 

 added, and the flask is warmed on the water-bath for five hours 

 with constant shaking. Concentrated acetic acid is next added 

 until the liquid is only feebly alkaline, then 250 c.c. of water, 

 and the flask is well shaken. After twelve hours the liquor is 

 filtered wiih the aid of a suction-pump. To 50 c.c. of the fil- 

 trate concentrated acetic acid is added to acid reaction, fol- 

 lovved by 20 c.c. of a ten per cent solution of lead acetate in 

 dilute acetic acid. After mixing, the liquid is diluted to a 100 

 c.c. with water, well shaken and filtered. Ten c.c. of the fil- 

 trate are decomposed with 5 c.c of H2SO4 (1:3) and 30 c.c. of 

 alcohol, the precipitate filtered after some time, washed with 

 alcohol, and the lead sulphate ignited and weighed in the 

 usual manner, and the amount of lead calculated. The 

 amount of lead (in grams) which has been obtained by the pro- 

 cess from 1 gram of dried pepper, may be described as the "lead 

 number." The figures given by the different kinds of pepper 

 are: 



Lead Number. 



White pepper 0.006 to 0.027 



Black pepper 0.054 " 0.075 



Husks 0.129 " 0.157 



Pepper dust 0.109 " 0.122 



The author concludes that this method, taken in conjunction 

 with the determination of the ash and sand and the microscop- 

 ical examination, should be of great assistance in estimating 

 the value of pepper. — Analyist. 



