376 Royal Society. 



The bud of a slip of Cissus hydrophora, stript of its bark, pre- 

 sents at its base a ligneous network which partially clothes the 

 inferior portion of the old wood, and escapes on every side in root. 



These two examples taken, the one in the monocotyledoneae, the 

 other in the dicotyledoneae, appear at first sight undeniable proofs 

 of the solidity of the doctrine of M. Gaudichaud ; yet, notwith- 

 standing, several phytologists, whilst they accept tlie facts, reject 

 the theory. This is because the question is not so simple as it ap- 

 pears. It is certain that it will not cease to be a subject of con- 

 troversy until there shall be an agreement as to the physiological 

 results of the process of grafting. 



The third point touches the scientific reputation of an excellent 

 man, who sat here during more than forty years, and whose 

 memory will be ever dear to us. Every one knows the work of 

 M. Desfontaines on the stems of palms. A German phytologist, 

 M. Hugo Mohl, treating of the same subject with more numerous and 

 more varied materials, and all the resources of the science such as 

 fifty years' progress has made it, advanced, a short time ago, that 

 the numerous ligneous fibres vvere not formed at the centre, but 

 at the circumference ; and that it was in crossing the older fibres 

 obliquely that they reached as far as the heart of the tree. From 

 this fact he concluded that M. Desfontaines had deceived himself; 

 yet it is not so, although the observations of M. Mohl are perfectly 

 accurate. The researches of M. Gaudichaud show that M. Des- 

 fontaines has very well observed and described what he saw, and 

 that M. Mohl, far from having overturned the work of this learned 

 man, has rendered it more unassailable by completing it. 



The considerations set forth in this Report sufficiently make 

 known the motives which have determined the commission to di- 

 vide the prize between M. Gaudichaud and one of his competitors, 

 M. Poiseuille, whose admirable works on the motion of the blood, 

 render him for the third time worthy of a distinguished testimony 

 of the esteem of the Academy. 



LXXIV. Proceedhigs of Learned Societies. 



ROYAL SOCIETY. 

 (Continued from vol. viii. p. 553.) 



1836. A PAPER was read, entitled " Additional Observations 



April 21. -^^ on Voltaic Combinations." In a letter addressed 

 to Michael Faraday, Esq., D.C.L., F.R.S. Fullerian Professor of 

 Chemistry in the Royal Institution, &c. By J. Frederick Daniell, 

 Esq., F.R.S. , Professor of Chemistry in King's College, London. 



The author has found that the constant battery, of which he de- 

 scribed the construction in a former communication to the Royal So- 

 ciety, might be rendered not only perfectly steady in its action, but 

 also very pow-erful ; as well as extremely efficacious and convenient 

 for all the purposes to which the common voltaic battery is usually 

 applied. With this view he places tlie cells which form the battery 



