fixtj years ago, by Dr. Uvedale j'' and at prefent adorns many of 
the gardens of this country. 
The Orniis is not the only fpecies of afh which produces Manna; 
the rotundifoUa and excelftor^ efpecially in Sicily, alfo afford this 
drug, though lefs abundantly. Many other trees and fhrubs have 
likewife been obferved, in certain feafons and fituations, to emit a 
fweet juice, which concretes oh expofure to the air, and may be 
nfidered as of the manna kind." In Sicily the three fpecies of the 
Fraxinus, mentioned above, are regularly cultivated for the purpofe 
of procuring Manna, and with this view are planted on the declivity 
of a hill, with an eaftern afped. After ten years growth, the trees 
firft begin to yield the Manna, but they require to be much older 
before they afford it in any confiderable quantity. Although the 
Manna exudes fpontaneoufiy upon the trees, yet in order to obtain 
more copioufly, incifions are made through the bark, by means of 
a fharp crooked inflrument ; and the feafon thought to be mofl 
favourable for inflituting this procefs, is a little before the dog-days 
commence, when the weather is dry and ferene. The incifions are 
firft made in the lower part of the trunk, and repeated at the diftance 
of an inch from the former wound, ftill extending the incifions up- 
wards as far as the branches, and confining them to one fide of the 
tree, the other fide being referved till the year following, when it 
undergoes the fame treatment. On making thefe incifions, which 
m 
^ Vide Hort. Kew. • 
c Dr. Cullen is certainly right in fuppofing « Manna a part of the fugar fo univer- 
fally prefent in vegetables, and which exudes on the furface of a great number of them ;" 
the qualities of thefe exudations he thinks are " very little if at all different." The 
principal trees known to produce thefe mannas in different climates and feafons, are the 
larch, [mde Murray Ap. Med. i. />. 17.J the fir, (lac. V. Engeftrom in Phyftogr, 
Saljkapets Handl. Vol. u P, 3. p. 144. j the orange, (De La Hire Hi/i. de Vacad. d.fc. de 
Poris^ 1708.J the walnut, (Hal. Stirp. Heh. N. 1624.; the willow, (Mouffet in Du 
Hamel. Ph/fique des arhres^ P. i. p. 152.) the mulberry, (Micheli in Tragioni Tozzetti 
Viagg^ ^ Tom. 6. p, 424.) oaks, fituated between Merdin and Diarbektr (Niebuhr 
• Befchreib F. Arab. p. 145. Otter, Foyage en Turquie et en Perfe^ Vol. 2. p. 264. j alfo 
oaks in Perfia near Khounfar (Otter. 1. c.) the al hagi Maurorum, or the hedyfarum alhagi 
of Linnaeus ; of this manna Dr. Fothergill prefented a fpecimen to the Royal Society, 
which he confidered as the Tereniabin of the Arabians, (Phil. Trayif. Vol. 43. p. 87.) 
the ciftus ladaniferus in fome parts of Spain produces a manna, which, in its recent ffate, 
has no purgative quality, and is eaten by the fliepherds: fo that fome fermentation feems 
neceffary to give it a cathartic power, (Vide Dillon' i Travels through Spaln^ p, 127.) 
' " • : • are 
