i6 



formed by an insect which abounded on the tamarisk. Others affirmed 

 that an insect, a coccus, punctured the tree, that the juice exuded and 

 dropped on the ground as described, and that the dissolving after sun- 

 rise was simply the evaporating of the fluid part of the exudation. 

 There was another substance known by the name of manna, and com- 

 monly employed in medicine. This was merely a sweet condensed 

 juice of certain plants, but especially obtained from an ash tree, 

 fraxlnus rotimdifolia, a tree indigenous to Italy and the south of 

 Europe, and found growing abundantly without culture in Calabria, 

 where collecting manna was a regular trade, commenced about the end 

 of July. 



The gatherers of manna made a horizontal cut in the trunk of the 

 tree, and on the following day a second cut was made, into which the 

 point of a maple leaf was fixed, while the stalk part was placed in the 

 first slit, thus forming a kind of cup to receive the exuding juice. 

 Sometimes they applied thin straws to the incisions, or pieces of twig, 

 on which the manna ran as it exuded, and so formed tubular pieces, 

 which were called Manna in Cannoli, and fetched a higher price than 

 that collected on leaves. The season for collecting manna was over by 

 the end of August. At one time, manna from Syria was in request, 

 but the Calabrian was thought better. In Mexico, a manna was 

 obtained which seemed to take the place of cheese, while in other 

 places a manna was eaten much in the same way as honey. There 

 seemed to be some relationship between these so-called mannas and 

 some of the sugars obtained by making incisions in the trunks of trees, 

 notably in the case of sugar maple. It was a well-known fact that the 

 juices of many trees and plants when made to exude, in a somewhat 

 similar way, did on the evaporation of the watery particles produce 

 substances akin to but differing from manna in their qualities and 

 properties. 



In the year 1849, Mr. Giles Munby read a paper before the British 

 Association at Birmingham, on the " Botanical Productions of the 

 Kingdom of Algiers," in which he called attention to a lichen, 

 L. Esculentus or Lecanorn esciilenta, as it was now named, which he 

 considered agreed more nearly than any other substance hitherto dis- 

 covered with the description of the manna on which the Israelites fed 

 during their wanderings in the desert. He mentioned that this lichen, 

 which was found on the sands of the desert, sprung up during the night 

 much in the same way as mushrooms. That during an expedition to 



