Starch-Sugar Present.Reducing Sugar Obtained.
per cent.per cent.
51·472
103·240
206·392
408·854

3rd. If the cane sugar originally present in genuine honey has been changed into invert sugar, and the honey solution is boiled with a slight excess of Fehling’s reagent, no substances capable of yielding sugar when treated with acids will remain undecomposed. Starch syrup, when subjected to this treatment, yields grape sugar in about the proportion of 40 parts to every 100 parts of the syrup used. The test is applied as follows:—14 grammes of honey are dissolved in 450 c.c. of water, and the solution is heated over the steam-bath with 20 c.c. of semi-normal acid, in order to invert the cane sugar present. After heating for half an hour, the solution is neutralised, and its volume made up to 500 c.c. 100 c.c. of Fehling’s solution are then titrated with this solution, which may contain about 2 per cent. of invert sugar (in case the sample examined is pure, from 23 to 26 c.c. will be required); 100 c.c. of Fehling’s reagent are next boiled with 0·5 c.c. less of the honey solution than was found to be necessary to completely reduce the copper. The reduced liquid is then passed through an asbestos filter, the residue washed with hot water, the filtrate treated with a slight excess of concentrated hydrochloric acid, and the solution heated for one hour on the steam-bath. Sodium hydroxide is now added, until only a very little free acid remains unneutralised, and the solution is made up to 200 c.c. Upon well shaking the cooled liquid, a deposit of tartar sometimes separates. 150 c.c. of the filtered solution are finally boiled with a mixture of 120 c.c. of Fehling’s reagent and 20 c.c. of water, and the proportion of grape sugar estimated from the amount of metallic copper obtained. (See p. [111].) When pure honey is submitted to the preceding process, the copper found will not exceed 2 milligrammes. The quantities of copper obtained when honey adulterated with various proportions of starch sugar was tested were about as follows:—

Starch Sugar
contained.
per cent.		Milligrammes of
Copper found.
1040
2090
30140
40195
50250
60330
70410
80500

Character
of Samples.		Dextrose.Levulose.Invert Sugar,
by Fehling’s
Method.		Cane
Sugar.		Total
Sugar.		WaterDry
Substance.		Not
Sugar.		Polarisation
after
Fermentation.		Residue of
Fermentation
when treated
with acid gave
Grape Sugar.		Milligrammes
of Copper
found by
Method 3.
per cent.per cent.per cent.per cent.per cent.per cent.per cent.per cent.degrees.per cent.mgr.
Adulterated with cane sugar....56·3919·4576·8420·8579·152·310·00·00
Adulterated with cane sugar
and water 		25·6325·4251·0610·6261·6736·4863·521·850·00·00
Adulterated with 15 per cent.
glucose syrup 		37·2031·8069·18..69·0018·5481·4612·46× 4·44·266
Adulterated with 65 per cent.
glucose syrup		21·7519·6041·30..41·3518·6581·3540·00× 2512·4366
Adulterated with 40 per cent.
glucose syrup		34·6123·8958·83..58·5017·8182·1923·69× 137·6196
Adulterated with 40 per cent.
glucose syrup and with
cane sugar.		25·4723·5149·047·0656·0419·9480·0624·02× 17·48·2192
Adulterated with 80 per cent.
glucose syrup		21·9212·8335·00..34·7518·1281·8857·13× 3415·2492

The tabulation on p. [127] exhibits the results obtained by the application of the foregoing tests to adulterated honey.[68]

The detection of paraffine in honeycomb is easily accomplished. Genuine bees’-wax fuses at 64°, paraffine usually at a lower temperature. The latter is not affected by treatment with concentrated sulphuric acid, whereas bees’-wax is dissolved by the strong acid, and undergoes carbonisation upon the application of heat. The amount of potassium hydroxide required for the saponification of one gramme of bees’-wax, as applied in Koettstorfer’s method for butter analysis (p. 71), widely differs from the quantities consumed by Japanese wax and paraffine. Mr. Edward W. Martin has obtained the following figures:—

Milligrammes K (O H)
required to saponify one gramme.
Bees’-wax7·0
Japanese wax212·95
Paraffinenone

18 out of 37 samples of strained and comb honey, examined in 1885 by the Mass. State Board of Health, were adulterated with glucose and ordinary syrup.