THE 
JOURNAL 
OF THE 
ROYAL HORTICULTURAL SOCIETY 
OF LONDON. 
I. On the Production of Honey-Dew. Translated in Abstract from 
a Memoir by M. Eoussingault {Comptes Hendus, Jan. 8, 1872), 
by W. T. Thiseltoist Dyek, B.A., B.Sc, F.L.S. 
[Read April 3, 1872.] 
On July 21, 1869, at Liebfrauenberg, the leaves of a Lime were 
coated on their upper surface with an extremely saccharine viscid 
matter. The tree, in fact, afforded an example of the production of 
honey-dew, a manna-like substance, which is frequently observable 
upon the Lime, the Black Alder, the Maple, and the Rose. I have 
myself noticed it upon a Plum-tree, and — which is a very rare 
occurrence — upon a young Oak.* 
On the 22nd the honey-dew was sufficiently abundant in the 
morning to fall in large drops upon the ground. It was a shower 
of manna. At three o'clock the saccharine matter no longer 
remained fluid upon the leaves which were exposed to the sun. It 
had sufficient consistency not to adhere to the fingers when touched ; 
• [A saccharine substance exudes from the leaves of Qmrcus mannifera in 
Kurdistan. (Lindley, Bot. Reg., May and June, 1840.) Such a secretion 
from the Oak is more than once alluded to by Latin poets. In the Golden 
Age — " durae quercus sudabunt vescida mella." (Virg. Ec. iv., 30.) Martin 
remarks (Virg, ii., 36) — " It is no uncommon thing to find a sweet glutinous 
liquor on Oak leaves."— W. T. D.] 
VOL. IV. B 
