

Miscellanies. 393 



tamen earn propria facilitate, vert it acdigerit. — Jour, desprogres des 

 Set. *et Inst. Medic ales. 1830. tome I. 



( 



6. Vegetable Physiology. — Circulation of Sap. — At the sitting of 

 the Academy of Sciences, on the 19th of Sept. a report was made by 

 M. de Mirbel on certain observations respecting vegetable anatomy 

 and physiology, communicated by M. Shultz, Professor of the Univer- 

 sity of Berlin. These observations tend to show a real circulation 

 in the great division of phanerogamous plants resembling that of the 

 blood in animals, and the proofs placed before the persons to whom the 

 communication was referred by the Academy, have led them to regard 

 his discovery as incontestable. In the year 1820, M. Shultz, while 

 examining the plant chelidony conceived the first idea of the circula- 

 tion in question, and afterwards having directed his researches to many 

 vegetables with one or two cotyledons, and belonging to different gen- 

 era, he inferred that this circulation was common to all the spe 

 M. de Mirbel remarks that it is astonishing that among so many ob- 

 servers who have devoted themselves to the study of animal and veg- 

 etable physiology no one should have remarked this fact, and still 

 more so that since it had been announced no person in France had 

 been able to prove its reality. The preparations for observing it are, 

 however, simple. M. Shultz raised by the aid of a sharp instrument a 

 portion of the epidermis or outer bark of the Ficus elastica leaving the 

 cellular tissue and the vessels of the stipule naked. A fragment of 

 this organ is plunged into water and placed before the microscope, 

 when the observer sees the whole vascular apparatus destined for the 

 circulation, composed of long parallel bundles of vessels connected 

 with each other by a loose net work of vessels of the same kind. In 

 these the sap is seen flowing in little capillary torrents. The com- 

 mittee of the Academy not thinking their first observations sufficient, 

 M. Shultz showed them the movement of the sap through the epi- 

 dermis of an entire leaf, a plant of chelidony, to the stalk of which it 

 was yet attached. A clear day is chosen, the microscope is so pla- 

 ced that its mirror shall reflect the rays of the sun, the leaf is moisten- 

 ed and placed so as to direct the sight upon a vein thin enough to 

 admit the passage of the light. By means of the transparency of the 

 tissue a scintillation is then observed, owing to the refraction of the lu- 

 minous ravs bv the particles which the sap carries along with it, and if 

 the vessels are near to the epidermis the direction of the current is 

 clearly manifest. 



1. Mot torn of living particles in all kinds of matter.- A memoir by 

 Robert Brown appeared in London in 1829, announcing that a micro- 

 scopic examination had proved "that all bodies organic and morgauic, 



