INSECTS PRODUCING WAX, RESIN, HONEY, MANNA. 89 



economy. Besides the different varieties of ash, 

 the tamarix, and seaweeds,* a sort of manna is pro- 

 duced in Australia and Van Diemen's Land by the 

 Eucalyptus resinifera. At certain seasons of the year 

 a sweet substance exudes from the leaves of this 

 tree, and dries in the sun, and when the wind blows 

 hard enough to shake the trees, the manna falls like 

 a shower of snow. Certain oaks, larches, pines, 

 cedars, etc., produce a similar substance. The cedar- 

 manna, which is brought from Mount Lebanon, is 

 the product of Pinus cedrus it sells for twenty or 

 thirty shillings an ounce. The manna collected by 

 the Arabs for food in the desert, is the product of 

 Hedysarum alhagi, L., a plant which is indigenous 

 over a large portion of the East. That of Mount 

 Sinai is obtained from the Tamarix before alluded 

 to. The Coccus manniparus infests this tree, from 

 which the manna exudes as a thick syrup, which, 

 during the heat of the day, falls in drops, but dur- 

 ing the night congeals and is gathered in the cool 

 of the morning. 



On beeswax I have little to say. The best and 

 whitest wax is that taken during the month of 

 March. The nature of wax has been very com- 

 pletely investigated by Dr. Levy of Paris, to whose 

 admirable paper (" Annales de Chimie," xiii. p. 438) 



* On the production of Mannite by seaweeds, see my paper in 

 " Comptes Eendus," Paris, 1st Dec., 1856. 



