622 
WHY DO BEES WORK IN THE DARK? 
anesthesia, also strong hyperemia of the brain and spinal marrow, and even apoplexia. 
Otherwise its action is similar to other narcotics. 
The very decidedly poisonous properties of H. fcetidus, which contains less of the 
second glucoside, is most probably due to a volatile principle, together with the true 
narcotic principle, helleborein.— Druggists’ Circular , April, 1866, p. 90. 
WHY DO BEES WORK IN THE DARK? 
BY CHARLES TOMLINSON, F.C.S. 
About two years ago a paragraph appeared in the 1 Chemical News ’ (April 30, 1864), 
and went the round of the papers, under the title of “ Why Bees Work in the Dark,” 
in which it was stated (1) “ that the change of honey from a clear yellow syrup to a 
solid mass is a photographic action; that the same agent which alters the molecular 
arrangement of the iodide of silver on the excited collodion plate, and determines the 
formation of camphor and iodine crystals in a bottle, causes the syrupy honey to assume 
a crystalline form.” In proof of this, M. Scheibler enclosed honey in stoppered flasks, 
some of which were kept in the dark while others were exposed to the light, when it 
was found that the sunned portion rapidly crystallized, while the honey kept in the 
dark remained perfectly liquid. (2.) “ We now see,” he says, “why bees are so careful 
to work in perfect darkness, and why they are so careful to obscure the glass windows, 
which are sometimes placed in their hives. The existence of their young depends on 
the liquidity of the saccharine food presented to them, and if light were allowed access 
to this the syrup would gradually acquire a more or less solid consistency; it would seal 
up the cells, and in all probability prove fatal to the inmates of the hives.” 
While I was on a visit to a village on the Dorsetshire coast at the end of July, 1864, 
some new combs were brought in containing virgin honey, when it occurred to me to 
test the observation on which the above theory is founded, and the more so since the 
remark that “light determines the formation of camphor and iodine crystals in a 
bottle,” I knew to be erroneous. Accordingly, I collected a small quantity of this new 
honey in two bottles, and wrapped one of them in several folds of stout paper, and left 
the other exposed. On my return to town early in August I placed the bottles in an 
east window, where they remained many months exposed to the cold of winter and the 
sun of spring, with the temperature often below freezing-point, and on warm days above 
70° Fahr. The honey in both bottles remained quite fluid, and the only change was 
the deposit in each bottle of a few bright crystalline grains. 
A still more perfect experiment was made in July, 1865. Being in the same Dorset¬ 
shire village, I procured some virgin comb that had never seen the light, squeezed it 
gently through clean linen, and received the stream of pure limpid honey into two 
eight-ounce white glass bottles. When these were nearly filled the stoppers were in¬ 
serted, tied over, and the bottles labelled. One was wrapped up in opaque paper, and 
the other was, a few days afterwards, exposed to the light on a window-frame, where it 
has remained ever since, exposed to the direct sunshine of summer, and to the cold of 
winter; but the honey, whether exposed to the light or covered, remains perfectly 
limpid after about eight months. 
A bottle of honey from Kosenthal, in Switzerland, was procured from Messrs. 
Fortnum and Mason. This, they said, was three years old, and improved by keeping. 
It was in a bottle of light-green glass, and had been in their shop window for a long 
time. I transferred a portion of this honey to a white-glass bottle, and it has been ex¬ 
posed to the light for about ten months, and is still (February, 1866) quite fluid. 
Virgin honey from Bromborough Pool, near Birkenhead, exposed to the light during 
many months, remains quite fluid; but old honey, i. e. gathered from combs of the 
second year, whether exposed to the light or not, soon became solid. So also honey 
from near Dunstable, gathered from a new comb, became solid, contrary to the above 
experience, whether exposed to the light or not. 
These facts sufficiently prove that “the sunned portions” of virgin honey do not 
always “ rapidly crystallize.” 
The specimens of new honey, then, had, with one exception, not solidified after many 
months’ exposure. I endeavoured to bring some Dorsetshire honey into the candied 
