THE TECHNOLOGIST. 



THE SOURCES OF MANNA. 



The Manna of commerce is the concrete juice of the flowering ash Ornus 

 Europcea and 0. rotundifolia, which flows out after incisions or insect punctures. 

 Manna is also procured from Fraxinus excelsior and parvifolia. It is im- 

 ported into this country under the name of flake manna, principally from 

 Palermo, Messina, and other ports of Sicily, and we obtain some through 

 Trieste and Leghorn. In 1842, 2,565 cwts. of manna, valued at £70,584, 

 were exported from Sicily. The manna is collected in August and September, 

 and terminates when the rainy season sets in. Incisions, about two inches 

 long, are made with a hooked knife, first in the lower part of the stem, and 

 are repeated daily, extending them perpendicularly upwards. In the dis- 

 tricts of Capace, Cinesi, and Fabarotto, where the best manna is obtained, 

 the manna ash does not form woods, as is commonly supposed, but is culti- 

 vated in separate plantations. These plantations generally present regular 

 squares, hedged in with Cactus Opuntia. The trees are planted in rows, 

 and are from two to eight inches in diameter, with stems from ten to 

 twenty-five feet high, which, from the first shoot, are kept smooth and 

 clean. The soil is carefully loosened, and kept free from weeds. After 

 the eighth year the trees yield manna, which they continue to do from ten 

 to twelve years, when they are cut down, and young shoots from the roots 

 trained ; one root-stalk frequently yields from six to eight new trees and 

 more. For the production of the manna young and strong shoots are 

 requisite ; but they are not tapped till the tree ceases to push forth any 

 more leaves, and the sap consequently collects in the stem. This period is 

 recognised by the cultivators from the appearance of the leaves ; sometimes 

 it occurs earlier than at others, and the collection of the manna takes place 

 either at the beginning of July or only in August. Close to the soil cross 

 sections are made in the stem, and in the lowermost sections small leaves 

 are inserted, which conduct the sap into a receptacle formed by a cactus 

 leaf. This is the way the manna in sortie is obtained. The incisions are 

 repeated daily in dry weather, and the longer they continue the more 

 manna is obtained. The stems are left uninjured on one side, so that the 



Q 



