MANNA. il3 



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

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

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

 The hest 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 ac|ueous 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 aiid 

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

 kinds of manna often amounts to 10 or 15 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 resembling a3sculin, namely Fraxln, CTI"0'", occurring 

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

 with ffisculin, in that of the horse-chestnut. Fraxin crystalii/es_ in 

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

 a faintly astringent and bitter taste. By dilute acids, it is resolvf-1 in- 

 to Fraxetin, C^"H«0^ and Glucose, C'^ff^-O". The presence of fnixmin 

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

 fluorescence of the alcoholic manna solution. The smallest ragment ot 

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

 same fluorescence. 



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

 Palermo) have been as follows : 



1869 1870 }^'^^. -,_ ..^„ 



2o4G cwt., val. £15,972. 1564 cwt., val. £10,220. 3038 c^^-t., val. £l9,o28. 



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

 represent the export of manna in 1870 thus:— '?7i camlli oSOJi mio. 

 (1155 cwt.), in sorte 18'J,GG4 kilo. (3676 cwt.). The United Kingdom 

 imported in the year 1870, 230 cwt. of manna, valiied at i*^*!.- 



In 1877 the exports of "canelli" from Messina were 42 /.J kilo- 

 grammes, and of the drug " in sorte " 52,874 kilogr.; total value, l-/,l4o 

 lire. 



Adulteration-It can hardly be said that manna is su^ect to 

 adulteration, though attempts to introduce a spurious \"^"^^^;^?^^J' 

 glucose have been recorded. But considerable skill and ".^fif "'J^^^f f e;!^ 

 been expended in converting the inferior sorts of nninna into va at lias 

 the aspect of fine natural Flake Manna, the manufacturer adin tt ng 

 ^o vvever the fiictitiousness of their product. The artificial Flake Ma n 

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



'^"POH hy Consul Dennis on the Cam- nento conuneraale del r.jno <V Italia nd 

 ^^anaNari,ationofSialyinlSm,lS,0 1870^ M;lano,^18a. ^^^ ^^ ^^^^ 



' Direzioae generale delle Gabellc-.Vor*. I^'aviijalion of the U.K. J or \b,0, V- l^^ 



