25. On the Existence of Crystals of Oxalate of Lime in Plants.
The latter crystals were observed, for the first time, by Rafn and Jurine, who regarded them as organs of which they knew not the use. They were then observed by M. de Candolle, who called them raphides, and gave a figure of them, which, however, is inaccurate. These crystals are really very regular tetraedrons. In many plants, as orchis, pandanus, ornithogalum, jacinthus, phytolaca decandria, mesembryanthemum deltoides, &c. they are very small, not being more than 1200 of a millimetre (.0002 of an inch) in width, and 110 (.004 of an inch) in length. But, in the tubercles of the Florence iris, they are as much as 150 (.0008 of an inch) in width, and 13 (.01312 of an inch) in length, so as to be easily capable of examination.—Bull. Univ. B. xi. 376.
26. Fallacy of Infusion of Litmus as a Test, by M. Magnus.
27. Tests for the Natural Colouring Matter of Wine.
28. Test of the Presence of Opium.
29. Denarcotized Laudanum.
30. Extraction of Morphia from Dry Poppy Heads, by M. Tilloy.
31. Preparation of Morphia.
M. Henry observed, at the same time, that, from experiments made at La Pharmacie Centrale, it appeared that much more morphia was obtained in those processes in which lime had been used to precipitate the morphia, than in those in which magnesia had been used.—Bull. Univ. C. xi. 225.