416 OLEACE^. 



according to Haussknecht, collect it from Quercus Vallonea Kotschy 

 and Q. persica Jaub. et Spach. These trees are visited in the month 

 of August by immense numbers of a small white Coccus, from the 

 puncture of which a saccharine fluid exudes, and solidifies in little 

 grains. The people go out before sunrise, and shake the grains of 

 manna from the branches on to linen cloths, spread out beneath the 

 trees. The exudation is also collected by dipping the small branches 

 on which it is formed, into vessels of hot water, and evaporating the 

 saccharine solution to a syrupy consistence, which in this state is used 

 for sweetening food, or is mixed with flour to form a sort of cake. 



A fine specimen of the Oak Manna of Diarbekir was sent to the 

 London International Exhibition of 1862. It constituted a moist soft 

 mass of agglutinated tears, much resembling an inferior sort of ash- 

 manna, and had an agreeable saccharine taste. 



A less pure form of this maima occurs as a compact, greyish, saccha- 

 rine mass, sometimes hard enough to be broken with a hammer. It 

 consists of sugary matter, mixed with abundance of small fragments of 

 green leaves, and has a herby smell and pleasant sweet taste. A sample 

 of it brought from Diarbekir, examined by one of us, yielded 90 per 

 cent, of dextrogyre sugar, which could not be obtained in a crystalline 

 state, though it exists in such condition in the crude drug. Starch and 

 dextrine were entirely wa.nting.^ 



A specimen furnished to Ludwig- by Haussknecht afforded much 

 mucilage, a small amount of starch, about 48 per cent, of dextrogyre 

 grape sugar, with traces of tannic acid and chlorophyll. 



Brkmcou Manna — This is a white saccharine substance which, in 

 the height of summer and in the early part of the day, is found adher- 

 ing in some abundance to the leaves of the larch (Pinus Larix L.), 

 growing on the mountains about Briancon in Dauphiny. It was 

 formerly collected for use in medicine, but only to a very limited ex- 

 tent, for it was rare in Paris in the time of Geoffi'oy (1709-1731), 

 and at the present day has quite disappeared from trade, though still 

 gathered by the peasants. A sj^ecimen collected for one of us near 

 Briancon in 1854, consists of small, detached, opaque, white tears, many 

 of them oblong and channelled, and encrusting the needle-like leaf of 

 the larch; they have a sweet taste and slight odour.^ Under the 

 microscope they exhibit indistinct crystals. 



Brian9on manna has been examined in 1858 by Berthelot, who 

 detected in it a peculiar sugar termed Melezitose, answering to the for- 

 mula C^'ff-^0"-hOm 



Several other saccharine exudations have been observed by travel- 

 lers and naturalists ; we shall simply enumerate the more remarkable, . 

 referring the reader for further information to the original notices. 



Pirus glabra Boiss. affords in Luristan a substance which, according 

 to Haussknecht, is collected by the inhabitants, and is extremely like 

 Oak Manna. It is stated by the same traveller that Salixfragilis L., 

 and Scro2)hularia frigida Boiss., likewise yield in Persia saccharine 

 exudations. A kind of manna was anciently collected from the cedar, 

 Pinus Cedriis L.^ Manna is yielded in Spain by Cistus ladaniferus 



^ Further particulars, see Fltickiger, ^ /^q^. cit. p. 35. 



Weber die Eklmimanna von Kurdistan, in ^ Hanbury, Science Pavers, p. 4.38. 



Archiv der Pharmacie, 200 (1872) 159. * Geoffroy, Mat. Med. ii. (1741) 584. 



