Vegetable Physiology for the Year 1836. 533 



Jablonski draws from his experiments the conclusion that 

 the plants continued to live only so long as the nutritive sub- 

 stances deposited in the albumen or in the cotyledons could 

 go through the chemical process necessary to vegetable life ; 

 as soon however as their combinations had arrived at a rela- 

 tive chemical neutrality, death was inevitable, and carbonic 

 acid and water did not appear to be adapted to the sustenance 

 of the new product from the organic substances. 



From these observations we come immediately to those 

 which have been made on the reception of various substances 

 by the roots of plants. Mr. G. Towers* has once more made 

 some experiments in order to ascertain whether coloured fluids 

 can be taken up by the roots in their natural state ; but nei- 

 ther infusions of log-wood nor of Brazil wood were absorbed 

 by the plant, and this served to confirm the observations of 

 Link and other German botanists. Towers employed for 

 these experiments plants of balsam ; and soon after Ungerf 

 made similar experiments on Lemna minor, which he grew in 

 tincture of cochineal, with and without an addition of alum, and 

 in an infusion of log-wood, but he could never observe the 

 reception of the coloured fluid. The Bibliotheque Universelle 

 de Geneve% gave an extract from Towers' s experiments, and 

 complains that he had paid no attention to the labours of 

 preceding naturalists, who had proved that plants, even with 

 their roots in the natural state, did take up coloured fluids. 

 The observations of De Candolle, sen., are here mentioned, 

 according to which coloured liquids had penetrated through 

 the spongioles. However these imperfect notices of De 

 Candolle are contrary to a vast number of negative observa- 

 tions which I, among others, have performed yearly. But 

 already, long before the appearance of De Candolle' s Phy- 

 siology, H. Schultz of Berlin had made known that he had 

 observed coloured liquid imbibed by a Chara, The obser- 

 vation is related in a very detailed manner ; yet I have never 

 been successful in repeating it, although I have made similar 

 experiments with a great quantity of Chara. Setting aside 

 this single case observed by Schultz in Chara, we are able to 

 infer, from unexceptionable observations which we possess, 

 that the colouring substance in the coloured fluids is not finely 

 enough divided to pass through the cellular tissue of vege- 

 tables, and that hence it is not taken up by the plant when 

 uninjured. On the other hand, it has been proved by various 



• Transact, of the Horticult. Soc. of London, Sec. Ser. vol. ii. Part I. 

 p. 41. — Bibliotheque Universelle de Geneve, No. 5, 1836. — Ann. de* Scien. 

 Nat., 1836, ii. p. 228.— Froriep's Notizen, No. 1078, Sept. 1836. 



f Influence of Soil on Diff". of Plants, p. 149. 



; Nouv. Ser. vol. i. Mai 1836-. 



