20 



to 100 cubic centimeters. The direct polarization was -|-6.8 0 , and 

 after inversion +5.2° at 30.5° C. 



According to Bechmann, 0 methyl alcohol precipitates in natural 

 honey only a small amount of carbohydrates, while in glucose honey 

 it precipitates large amounts of the starch dextrin, so that a natural 

 honey can thus be distinguished from an adulterated honey. By this 

 method honey dew honey can be distinguished from one adulterated 

 with glucose. 



Also, most honey adulterated with glucose gives a red color when 

 treated with iodin in potassium iodid solution, while honeydew 

 honeys do not give this reaction. This test may also serve to dis- 

 tinguish honeydew honeys from glucose honeys. 



Absolute alcohol precipitates in the honey a large amount of 

 gummy matter which is strongly dextrorotatory. Twenty grams of 

 honey (sample Xo. 3) was diluted to 20 cubic centimeters with water 

 and absolute alcohol carefully added, a little at a time, and well 

 mixed by shaking until the volume was completed to 250 cubic centi- 

 meters. On standing several days the alcohol solution was filtered 

 off, and the gummy mass washed with alcohol and dissolved in hot 

 water, an aliquot part dried and weighed, and an} 7 reducing sugar 

 determined and deducted from the weight. The precipitate amounted 

 to 9.93 per cent, which is about equal to the percentage of dextrinous 

 matter determined in the fermentation residue as dextrose. 



The alcohol was removed from 100 cubic centimeters of the honey 

 filtrate and the residue clarified with aluminum cream and made up 

 to 100 cubic centimeters and filtered. The solution gave a polariza- 

 tion of — 0.5°, and after inversion, of — 1.5° at a temperature of 

 28.8° C. The filtrate from sample No. 39, treated as above, gave a 

 direct polarization of — 0.8°. 



This latter method was recommended by Dr. H. W. Wiley, & as ac- 

 cording to Konig and Karsch, c the levorotation of a honey solution 

 from which the dextrinous bodies have been separated by absolute 

 alcohol shows a pure dextrorotatory honey and distinguishes it from 

 a glucose honey. 



Sucrose. — The sucrose content in the honeydew honeys is somewhat 

 high, but 8 per cent sucrose has been found in floral honeys. Ac- 

 cording to Konig,^ the content has even been found to be as high 

 as 12 per cent in pure honey. 



° Leffmanu and Beam. Food Analysis. Philadelphia, 1901, p. 135. 

 & Letter of Dr. H. W. Wiley, December 1, 1906. 

 c Ztschr. Analyt. Chero., 31 (1895), p. 1. 



d Untersnchung landwirtsehaftlich und gewerblich wiehtiger Stoffe. Berlin, 

 1891, 1. ed., p. 463; 1906, 3. ed., p. 589. 



Bui. 17 



