MANNA. • 413 



of a mixture of Cane-sugar and Levulose. He found however that an 

 aqueous solution of manna deviates powerfully to the right, a fact 

 which he considers due to the presence of a large proportion of Dextrin. 

 The best kinds of manna, according to Buignet, contain about 20 per 

 cent, of dextrin ; the inferior much more. 



In our experiments we have not succeeded in isolating either dextrin 

 or cane-sugar. There is present, even in the finest manna, a small 

 amount of a dextrogyre mucilage, which is precipitated by neutral 

 acetate of lead, and yields mucic acid when boiled with concentrated 

 nitric acid. 



Ether extracts from an aqueous solution of manna a very small 

 quantity of red-brown resin, having an offensive odour and sub-acrid 

 taste ; together with traces of an acid which reduces silver-salts and 

 appears to be easily resinified. The quantity of water in the inferior 

 kinds of manna often amounts to 10 or 1.5 per cent. The finest manna 

 affords about 3"6 per cent, of ash. 



The greenish colour of certain pieces of manna was formerly attri- 

 buted to the presence of copper, till Gmelin, on account of the fluor- 

 escence of the solution, ascribed it to JEsculin. It is in reality produced 

 by a body much i-esembling sesculin, namely Fraxin, C^ff^O^", occuiTing 

 in the bark of the manna-ash and of the common ash, and together 

 with sesculin, in that of the hoi-se-chestnut. Fraxin crystallizes in 

 colourless prisms, easily soluble in hot water and in alcohol, and liaving 

 a faintly astringent and bitter taste, ^y dilute acids, it is resolv<Ml in- 

 to Fraxetin, C*"ffO^ and Glucose, C*ff-0*. The presence of fraxin in 

 manna, especially in the inferior sorts, is made apparent by the faint 

 fluorescence of the alcoholic manna solution. The smallest fragment of 

 the bark of the ash or the manna ash immersed in water displays the 

 same fluorescence. 



Commerce — The exports of manna from Sicily * (chiefly from 

 Palermo) have been as follows : — 



1869 1870 1871 



2546 cwt., val. £15,972. 1564 cwt., val. £10,220. 3038 cwt., vaL £19,528. 



About half the quantity is sent to France. Italian commercial statistics" 

 represent the export of manna in 1870 thus : — in canelli 58,691 kilo. 

 (1155 cwt.), in sorte 18G,664 kilo. (3676 cwt.). The United Kingdom 

 imported in the year 1870, 230 cwt. of manna, valued at £44^7.^ 



In 1877 the exports of "canelli" from Messina were 4273 kilo- 

 grammes, and of the drug " in sorte " 52,874 kilogr.; total value, 127,145 

 lire. 



Adulteration — It can hardly be said that manna is subject to 

 adulteration, though attempts to introduce a spurious manna made of 

 glucose have been recorded. But considerable skill and ingenuity have 

 been expended in converting the inferior sorts of manna into what has 

 the aspect of fine natural Flake Manna, the manufacturei's admitting 

 however the factitiousness of their product. The artificial Flake Manna 

 has the closest superficial resemblance to very fine pieces of the natural 



^ Report by Consul Dennis on the Com- mento cominerckde dd regno d'lialia nel 



nierce and Navujation ofSicUij in 1869, 1870 1870, Milano, 1871. 



««d 1871. ^Annual Statement of the Trade and 



-DirezionegeneraledelleGabelle — Mori- Navigation of the U.K. for 1870, p. 102 



