112 Scientific Intelligence. 



is unalterable in the air, insoluble in ether, alcohol, naphtha, and chlorid 

 of phosphorus. Spirits turpentine dissolves it slightly at an elevated 

 temperature. It is much less combustible than ordinary phosphorus, 

 and takes fire in the air at 260° C, which is the temperature at which 

 it passes to the state of phosphorus when heated in an inert gas. A 

 solution of boiling potash attacks it, with a disengagement of phosphu- 

 retted hydrogen not spontaneously inflammable ; but at the same time 

 the phosphorus passes to the black condition indicated by Thenard. 

 According to M. Schrotter, phosphorus will pass to the black modifica- 

 tion only after first having assumed the red. 



6. Observations on Manna; by J. Stettner, (Chemical Gazette, July, 

 1848, No. 137, p. 261; Archiv. der Pharm., vol. liii, p. 194.)— The 

 author gives the following account of the cultivation of the manna ash 

 and the collection of the manna, from observations made in Sicily du- 

 ring the summer of 1847, The manna ash, Fraxinus ornus, in the 

 manna districts of Capace, Cinesi and Fabarotto, where the best manna 

 is obtained, does not form woods, as is generally supposed, but is culti- 

 vated in separate plantations. These plantations generally form regular 

 squares, hedged in with Cactus opuntia. The trees are planted in rows, 

 and are from 2 to 8 inches in diameter, with stems from 10 to 25 feet 

 high, which from the first shoot are kept smooth and clean. The soil 

 is carefully loosened and kept free from weeds. After the eighth year 

 the trees yield manna, which they then continue to do from ten to 

 twelve years, when they are cut down, and young shoots from the roots 

 trained ; one root-stock frequently yields from six to eight new trees 

 and more. For the production of the manna, young and strong shoots 

 are requisite ; but they are not tapped before the tree ceases to push 

 forth any more leaves, and the sap consequently collects in the stem. 

 This period is recognized by the cultivators from the appearance of the 

 leaves; sometimes it occurs earlier than at others, and the collection of 



the manna takes place either at the beginning of July or only in Au- 

 gust. Close to the soil cross sections are made in the stem, and in the 

 lowermost sections small leaves are inserted, which conduct the sap into a 

 receptacle formed by a cactus leaf; this is the way the manna in sorte 

 is obtained. The incisions are repeated daily in dry weather, and the 

 longer this continues the more manna is obtained. The stems are left 

 uninjured on one side, so that the manna runs down the smooth bark 

 more easily. The next year the uninjured side is cut. The Manna 

 cannelata is obtained from the upper incisions, more than forty of which 

 may be counted on one tree. The sap is there not so fat as below, and 

 consequently dries more easily into tubes and flat pieces. After the 

 manna hns been removed from the trees, it has further to be dried 

 upon shelves before being packed in cases. The masses Left adhering 

 to the stems after removing the inserted leaves are scraped off, and 

 constitute the Manna cannelata in fragmentis. Cannelata, Can. tn 

 fragm. and Capace are collected at the same time from one stem — -the 

 more Cannelata, the younger, and the more Capace or Gerace, the 

 older the stem. In Sicily the latter is designated in sorte, and is prob- 

 ably the most active. Dry and warm weather is essentially requisite 

 for a good harvest. 



