REPOBT OF THE CHEMIST. 115 



DETECTION OP ADULTERATION WITH GLTTCOSE. 



I have never yet found a genuine honey which was not l£evo-rotatory. 

 Nevertheless the turning of the polarized plane to the right is not con- 

 clusive evidence of the presence of glucose unless the amount of deflec- 

 tion is more than 100° of the cane-sugar scale when the amount of the 

 substance taken for examination is the same in weight as that required 

 by jiure sucrose to read 100 divisions. 



After treatment with .1 volume of hydrochloric acid and heating to 

 70° C. the solution is cooled and repolarized. If now it still reads to the 

 right the presence of starch sirup is established. In such cases, after 

 inversion, the free acid is neutralized and the reducing sugar deter- 

 mined by an alkaline copper solution. The percentage of this sugar will 

 fall much below 70, unless a large part of the adulteration has been due 

 to cane- sugar. 



OANE-SUGAB (SUCROSE). 



A thick sirup made of cane-sugar is also used to adulterate honey. 

 There is only one reason why it is not more extensively employed, viz, 

 its tendency to crystallize. On this account it can only be used m small 

 quantities. There would be no difiSculty in detecting added cane-sugar 

 in honey were it not for the fact that we cannot definitely say how much 

 of this substance is present in the genuine article. In the analysis 

 given by Seiben,* the mean of sucrose in the sixty samples was 1.08 

 per cent. ; in one case, however, it amounted to 8 per cent. In the an- 

 alyses given in this paper the mean percentage of sucrose in eight sam- 

 ples of genuine honey was 2.87, and in seven samples which appear to be 

 genuine 2.74, and in the samples contained in Table No. Ill, sixteen in 

 number, which may be genuine, 1.77 per cent. Judging from these an- 

 alyses I woidd say that it is a rare thing to find a genuine honey which 

 contains more than 4 per cent, sucrose. In the two samples of California 

 honey, Nos. 41 and 42, the percentage of sucrose is very high. Doubt- 

 less the kind of flower and climate have much to do with this, and it 

 would not be strange if California honey, produced in the unique con- 

 ditions of climate and flora which there obtain, should develop some 

 constant difference from honeys produced in other parts of the world. 



DETECTION OF CANE-SUGAR IN HONEY. 



The presence of cane-sugar in honey is easily detected by the process 

 of double polarization. Illustration : Sample No. 14; weight of sample 

 taken, 16.2 grams in 100 cubic centimeters ; length of observation tube, 

 400 millimeters; reading of scale, — 15; divide this number by 2 gives, 

 — 7.5 divisions, correct reading for a 200-millimeter tube. After inver- 

 sion the reading in a 220-millimeter tube was — 20.5 divisions; tempera- 

 ture, 23° ; difference of the two readings, 13 divided by 144 — 11.5 equals 

 9.81 per cent., equals sucrose present. 



The method of double reduction of Fehling's solution once before and 

 once after the inversion of the cane-sugar can also be employed. The 

 optical method is quicker, and when properly conducted more reliable 

 than the method by reduction. K the rotatory power of the sample is 

 quite small, two ov three times the normal quantity may be taken, and 

 the polarization conducted in a 400 or 500 millimeter tube. 



INYERTED CANE-SUGAR. 



As an adulterant of honey the iaverted cane-sugar is much superior 

 to the sucrose itself. It does not crystallize, and when properly made 



• Op. cit 



