582 
BEES AND BEE-KEEPING. 
bees gather nectar yield mostly cane sugar,* but this 
undergoes inversion through the action of the salivary 
secretion of the bee (see page 377 et seq.), and the 
two forms of glucose before mentioned are produced. 
The names dextrose and levulose imply right-hand 
and left-hand sugar, and need some explanation, since 
the properties to which they refer are the chief aids 
in detecting adulteration in honey, a question in 
which every bee-keeper has the deepest interest. To 
the mere chemist these two forms of sugar are 
identical, the composition of each being: carbon, 6 
atoms; hydrogen, 12 atoms; oxygen, 6 atoms. Some 
difference, however, exists in the arrangement of these 
atoms, since the first is easily crystallisable, is not 
especially sweet, and turns the plane of polarisation 
to the right ; the second is non -crystallisable, is 
very sweet, and turns the plane of polarisation to 
the left. 
The whole question of polarisation is complex, but 
still a sufficiently clear idea of the involved point can 
be conveyed in a popular manner. Ordinary light is 
regarded as consisting of waves, or vibrations, travel- 
ling with inconceivable velocity, the various waves 
making up a beam moving in every possible plane. 
* It has been calculated that one fuchsia blossom yields *117 grains 
of sugar, five-sixths of which are cane sugar; one Claytonia, -oo6 grains, 
two-thirds of which are cane sugar; each flower of the garden pea, -153 
grains, almost wholly consisting of one or both of the glucoses ; vetch, 
•002 grains per flower ; red clover, the same amount. Accepting this 
grain per blossom as accurate, 3,500,000 visits must be paid to gather 
I lb. of sugar. But all must know that the amount of honey in any 
blossom depends much on external conditions, and is liable to very’ con- 
siderable variation ; while the supposition that clover only yields one 
seventy-seventh of that furnished by the garden pea (see page 306, 
Vol. I.), would appear to need verification, and I, after careful attention 
to the point, venture to think it very wide of the truth. 
