808 FOODS AND FOOD ADULTERANTS. 



per cent sucrose. la the 2 samples of California honey, Nos. 41 and 42, the percent- 

 age of sucrose is very high. Doubtless the kind of flower and climate have much to 

 do with this and it would not be strange if California honey, prodnced in the unique 

 conditions 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 de- 

 tected by the process of double polarization. Illustration : Sample No. 14, weight of 

 sample taken, 16.2 grams in 100 cc, length of observation tube" 400 mm; reading 

 of scale, 15; divide this number by two gives 7.5 divisions, correct reading for a 

 200 mm tube. After inversion the reading in a 220 mm tube was 20.5 divisions, 

 temperature, 23 ; difference of the two readings 13 divided by 144 11.5, equals 9.18 

 per cent ; equals sucrose present. 



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

 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. If the rota- 

 tory power of the sample is quite small, two or three times the normal quantity may 

 be taken and the polarization conducted in a 400 or 500 mm tube. 



3. Inverted Cane Sugar. 



As an adulterant of honey the inverted cane sugar is much superior to the sucrose 

 itself. It does not crystallize, and when properly made is palatable and wholesome. 

 Sucrose is usually inverted by heating with an acid, and for commercial purposes sul- 

 phuric acid is the one generally employed. The difficulty of removing all traces of 

 this acid renders the detection of inverted sugar somewhat easy by the presence of 

 the traces of the sulphuric acid which still remains in the solution. It is now said, 

 however, that inverted sugar is made in large quantities by treatment with brewer's 

 yeast and without the use of acids of any kind. When added to honey in large quan- 

 tities it can be detected by its great levorotatory power, which, however, decreases 

 rapidly as the temperature rises. At 23 a pure invert sugar solution would mark 

 32.5 divisions. In the present state of our knowledge it would be difficult to detect 

 the addition of a small quantity of invert sugar to honey. From the above studies it 

 appears that pure honey is essentially composed of invert sugar, together with a cer- 

 tain portion of sugars optically inactive (anoptose), water, a small quantity of albu- 

 minous matter, ash, and solids not sugar, i. e., those which, while resembling sugar in 

 chemical composition, are yet not detected in the ordinary process of analysis. 



In addition to the above it appears from the results of a large amount of work done 

 at my suggestion by Mr. G. L. Spencer, that pure honey contains a varying amount 

 of dextrin, which in some cases amounts to as much as 4 per cent.* 



This investigation is still in progress, and therefore its result can not yet be an- 

 nounced. The presence of. dextrin in honey doubtless accounts for the phenomenon 

 that in some samples of pure honey the levorotatory power is very small, or, accord- 

 ing to some authors, entirely disappears, which would not be the case except for the 

 presence of some highly dextrorotatory substance. 



AGRICULTURAL DEPARTMENT, WASHINGTON, D. C. 



* Since this investigation was undertaken Amthor (Report, anal. Chem., 1885, p. 163) 

 had shown that honey gathered from pine forests contains dextrin, often in such quan- 

 tities as to become dextrorotatory. Klinger claims that this phenomenon is not exclu- 

 sively confined to honey of coniferous origin. According to our observations, even 

 left-handed honey may contain marked quantities of dextrin. If this be so it can 

 hardly be true, as W. Lenz (Chem. Zeit., 8, 613) affirms that after fermentation honey 

 yields no optically active substance. 



