532 Prof. Meyen's Report of the Progress of 



to nourish the plant ; or whether these nutritive substances are 

 taken up, at least in their elements, from without. Unger 

 (/. c. p. 136) finally arrives at the conclusion, " that the pro- 

 cess of vegetation is neither able to produce new elementary 

 substances out of the substances presented to it, nor even to 

 arrange those already present ; from this, however, it imme- 

 diately follows indirectly, that plants also must necessarily 

 take up their inorganic substances, such as carbon, hydrogen, 

 oxygen, and nitrogen, from the external world." 



Jablonski * has once more endeavoured to prove by ac- 

 curate experiments, that the inorganic substances which plants 

 contain are received from without. In order to refute the 

 well known experiments of Schrader, which were to prove 

 from observations that the process of vegetation was able to 

 form alkalies, earths and metals, Jablonski performed similar 

 experiments, which afforded the following result. The flowers 

 of sulphur, which were also employed in these observations, 

 were purified before the experiments by digesting them in 

 muriatic acid, and it was proved by this operation that a 

 quantity of oxide of iron, silica and lime was mixed with the 

 flowers of sulphur ! In perfectly clean flowers of sulphur, 

 the seeds of various plants were sown, but they attained only 

 a very low state of development, even when they were watered 

 with water containing carbonic acid. The Dicotyledones de- 

 veloped slowly their cotyledons, but the plumula exhibited no 

 inclination to lengthen itself; and after from three to four 

 weeks, all the plants were dead. 



Jablonski then made the same experiments with flowers of 

 sulphur purchased as pure from a druggist; these on being 

 burnt left behind 4 per cent, of a carbonaceous mass which 

 gave 1 J per cent, of ashes, of oxide of iron, lime and silica. 

 Cabbage seeds which were sown in these flowers of sulphur 

 soon germinated, and attained a height of 4 inches above the 

 sulphur, till at last they died between the 7th and 10th week, 

 without having increased within the three latter weeks in any 

 perceptible degree. This last experiment terminated exactly 

 in the same way as the experiments of Lassaignes, whose plants 

 of buckwheat in cleansed sulphur put forth in fifteen days 

 stems six centimetres high. Lassaignes at that time analysed 

 the plants thus sown, and found their ashes to have exactly the 

 same composition with a quantity of the seed equal to that 

 from which the plants had grown, f 



• Contribution to the solution of the question, whether by the process 

 of vegetation bodies chemically indecomposable can be formed? — Wieg- 

 mann's Archiv, 1836, p. 206—212. 



[f The entire series of researches on this subject recited above bears 

 importantly on that of Mr. Reade's paper on the solid materials of the 

 ashes of plants, in our last Number, p. 413,—Edit.] 



