388 Miscellaneous Intelligence. 



This substance has some analogy with starch, imiline, gelatine, 

 &c, but differs from them in forming a granulated mass when its 

 aqueous solution is evaporated, by its specific gravity, and other 

 qualities.— Ann. de Chimie, xxiv. 209. 



III. Natural History. 



1. Amici's Microscopical Observations.— Professor Amici, of Mo- 

 dena, has published the results of his microscopical observations on 

 various plants, in the Proceedings of the Italian Society of Sciences at 

 Modenu. We have only seen an account of these researches in the 

 Bibliotlieque Universelle, xxiii., and have made the following abstracts 

 from it. The work of Amici is illustrated by several large plates, of 

 the accuracy of which, and also of the descriptions, his abilities and 

 means are securities. 



Circulation of the Sap in Vegetables. Caulinea fragilis. — Corti first 

 discovered the motion of the sap in plants, and among others in an 

 aquatic plant of which he has not given the name, but only an im- 

 perfect figure ; it proved to be that of which Wildenow made a genera 

 under the name of Caulinea. Some time since Amici observed and 

 described a similar phenomenon, in the chara vulgaris: the circulation 

 was seen in the vessels of this plant, always in the same direction, and 

 was supposed to be caused by small crowns of green particles lining 

 the internal membrane of the tube. 



A transverse section of the Caulinea, viewed by powers of 60 and 

 150, appeared as a polygon of 8 rays, each formed by a range of 

 circular bodies ; the centre was occupied by a large tube, surrounded 

 by a bundle of smaller tubes parallel to each other, and in which 

 were diaphragms at a considerable distance one from another. These 

 vessels contained only air, which escaped in bubbles, when they were 

 cut under water ; all the other apertures in the section, are those 

 of the vessels which conduct the sap, and which also have dia- 

 phragms, more or less distant from each other. No proper trachse 

 or porous tube was discovered. 



Each cavity of the Caulinea formed a particular vessel, in which 

 the liquid moved, independent of the circulation in the neighbouring 

 vessel, and in a manner analogous to the movements before observed 

 in the vessels of the Chara. The fluid contains visible concretions 

 which moving with it indicate its course, and the velocity of its 

 motion in different parts. These particles are globular, of the same 

 size in .the same vessel, but varying in different parts of the plant. 

 The motion is as follows : — globules ascend on the one side of the 

 tube containing them and the liquid until they reach a diaphragm, 

 when they move horizontally to the opposite side, and descend, 

 until coming to a diaphragm beneath, they move horizontally in the 



