on the Effects of Charcoal on VegetatioJi. 305 



it was certainly new : but I quote in proof of that assertion a 

 passage from Schrank's Natural History of Plants^ to which my 

 attention has been called : ** Senebier found that leaves in car- 

 bonated water, or when mixed with tincture of gall-nuts, vegetate 

 longer and better than when in common water. He also found 

 that leaves which, when exposed to the sun in water, had ceased 

 to develope oxygen, did so again, as soon as carbonate was added 

 to the water. In some parts of Sweden the barley-fields were 

 manured with charcoal, and the crop was twenty times more 

 abundant. Rafn found that the different sorts of corn grew 

 best in the sorts of earth in which charcoal predominated." 

 Leuch's Volhtandiger Du7igerlehre, ii. 1832, p. 310. to 313. and 

 p. 541. to 550., is said, according to the Allgemeinen Afizeiger 

 der Deutschen^ to contain observations on charcoal ; but I have 

 not been able to get a sight of this book. 



During the last year many interesting cuttings of plants rooted 

 in pure charcoal, some of them very difficult sorts to root, of 

 which the following are examples : Dodoni^^a humilis, Corrae^a 

 alba, C. rufa, Magnolm purpurea, M. glauca, M. humilis, M. 

 fuscata, Myrtus moschata, Eutaxia Baxter/, E. Twyrtifolia, Cho- 

 rozema Mangles/, Priinus Laurocerasus, Polygonum com- 

 plexum, Hales/a tetraptera, Witsenm corymbosa, Xaurus Ben- 

 zoin^ Polygala cordifolia, Taxus macrophylla, T. baccata, Pinus 

 canadensis, Andrew'sm glabra ; several species of Melaleuca, 

 Diosma, Phylica, Grevillefl;, Chir6n/« ; Azalea indica, &c., i^rica 

 ignescens, tendrils of Fitis vinifera, A^erium Oleander, &c. Also 

 of hothouse plants, Jacquinm arborea, J. mexicana, J. armillaris, 

 /^lex paraguaiensis, /. acutangula, Malpighia ^quifolium, M. 

 glabra, M. coccifera, M. fuscata, Ardisia japonica, A. colorata. 

 Citrus Z'uxifolia, C Aurantium, C. Medica, Limbnia trifoliata, 

 Guaiacum sanitum, G. officinale, Francisc^a Hoppeawa, Bau- 

 hinm aculeata, Stiffl;m insignis, Illicium anisatum, I. floridanum, 

 Schot/a speciosa, Comocladia integrifolia, Copaifera sp. Mexico, 

 Plumierz'a lactea, P. angustif51ia, Gmelina sinuata, Chitonia 

 mexicana, Z/aurus nitida, I'nga Sdman, Qudrea trichilioides, 

 Curcas drastica, Dombeya acerifolia, Schrank/« aculeata, Blitt- 

 nera catalpceibWa, -(Acacia ^amariscina, Karwinskia glandulosa, 

 Chamaedorea Schiedean<a;, Bactris setosa, Caryota sobolifera, 

 Doryanthes excelsa, and others. 



These examples may suffice ; as they yield a sufficient proof 

 that plants of the most opposite families root in pure charcoal, 

 and mostly much better and easier than in sand or earth ; and 

 there are many of the sorts above mentioned which heretofore 

 could not be successfully propagated in the Botanic Garden at 

 Munich. 



The propagation of Cacti in charcoal, again, produced the 

 most favourable results. Most of the leaves and parts of 



X 2 



