MARCH.] THE NURSERY. 279 



In Sicily the three spices above mentioned, with the view of ob- 

 taining manna from them, but more particularly the first, are plant- 

 ed on the declivities of hills, having eastern aspects. After ten 

 years growth, the trees first begin to yield manna, but they require 

 to be much older, before they afford it in any considerable quantity. 

 Although the manna exudes spontaneously from the trunks and 

 branches, yet in order to obtain it more copiously, incisions arc 

 made through the bark, by means of a sharp crooked instrument ; 

 a slice of which, is taken off, about three inches in length and two 

 in breadth ; they leave the wounds open, and by degrees the manna 

 runs out. The season thought to be most favourable for instituting 

 this process, is a little before the dog-days commence, when the 

 weather is dry and serene. The incisions are first made in the 

 lower part of the trunk, and repeated, at the distance of an inch or 

 two from the former wound, still extending them upwards as far as 

 the branches, and confining them to one side of the tree ; the other 

 side being reserved till the year following, when it undergoes the 

 same treatment. On making these, a thick white juice immediate- 

 ly begins to flow, which gradually hardens on the bark, and in the 

 course of eight days, acquires the consistence and appearance, in 

 which the manna is imported ; when, it is collected in baskets, and 

 afterwards packed in large chests. Sometimes the manna flows in 

 such abundance from the incisions, that it runs upon the ground, by 

 which it becomes mixed with various impurities, unless prevented, 

 which is commonly attempted, by interposing large concave leaves, 

 stones, chips of wood, Sec. The business of collecting it, generally 

 terminates in those countries in September, when the rainy season 

 sets in. 



That manna is got in quantities on the leaves of trees, is an opi- 

 nion taken from the doctrine of the ancients, and received as in- 

 contestible without consulting nature ; for all those who are em- 

 ployed in the gathering of it, know of none that comes from the 

 leaves ; therefore, that with which the Israelites were so peculiarly 

 favoured, could only have been produced through miraculous means, 

 and is consequently out of the province of the naturalist. The best 

 manna is what exudes from the tree very slowly, and is collected 

 clean, this is always more dry, transparent, and pure ; for when 

 it flows copiously it concretes into a course, brown, unctuous mass* 



Methods of propagating Trees and Shrubs by Layers. 



There are few trees or shrubs, if any, but may be increased in 

 this way. The nursery gardeners who want to propagate large 

 quantities of various hardy kinds, of which they cannot easily pro- 

 cure seeds, and which by experience they do not find to grow free- 

 ly by cuttings ; establish, what they call, stools, of the different kinds 

 intended to be propagated, particularly of the deciduous tribe, and 

 also, some evergreens. For this purpose, they plant in different 

 quarters, stout healthy plants, at the distance of four or five feet 

 irom one another every way, and head them down ; these throw 

 out near the earth a number of young shoots, some, of which may 



