334 M even's Report for 1839 on Physiological Botany, 



sodium, but considerable quantities of chloride of potassium ; 

 while in the old plants there is less chloride of potassium, *but 

 a nearly equivalent quantity of chloride of sodium. The quan- 

 tity of carbonate of soda is nearly equal in both young and old 

 plants. The young plants of Salsola brachiata also contain 

 less chloride of sodium than the old ones, while the quantity 

 of carbonate of soda remains the same. 



M. Gobel thinks it is perfectly immaterial whether young or 

 old plants are used for procuring soda, for the quantity of car- 

 bonate of soda is the same in both cases. The plants might 

 therefore be burnt at any time, and the value of the impure 

 soda would not materially differ. The analyses of Halimo- 

 cnemis crassifolia, Salsola clavifolia an&brachiata, both in their 

 young and old state, show " that the quantity of soda has 

 remained nearly constant in all." The quantity of potash is 

 always greater in the young plants than in the old ones, and 

 strikingly so in Salsola clavifolia ; so that one might really be 

 led to believe, " that in the course of the vegetative process 

 potash is metamorphosed into soda, or, at least, is got rid of 

 in some manner or other." If this were correct, it would cer- 

 tainly be a wonderful discovery, but I may be allowed to pro- 

 pose a question which is not answered in M. Gobel's treatise : 

 Were the old specimens of the three above-mentioned plants 

 (which M. Gobel did not collect himself) from exactly the 

 same spot as that from Which, in the same manner, M. Gobel 

 gathered the young ones ? Probably this was not the case, 

 and as all these salts are extracted from the soil, a difference 

 therein will of course make a change in the results of the ana- 

 lyses. We must therefore consider this metamorphosis of 

 one substance into the other as yet unproved. M. Gobel also 

 states, thflt in other plants the quantity of potash is larger in 

 the young than in the old ones. With respect to the relative 

 value of the Halophytes for the fabrication of soda, M. Gobel 

 gives the following list: — 1. Salsola clavifolia, young dried 

 individuals, 42 per cent. ; 2. Halimocnemum caspium, young 

 specimens, 22*9 per cent. ; 3. Salsola Kali, young specimens, 

 25 per cent.; 4. Kochia sedoides, old specimens, 9' 16 per 

 cent.; 5. Salsola brachiata, young specimens, 33 per cent.; 



6. Halimocnemis crassifolia, young specimens, 30 per cent. ; 



7. Tamarioc laxa, young specimens, 33*6 per cent. ; Anabasis 

 aphylla, young specimens, 19 per cent., &c. 



On the movement of Saps in Plants, 

 The so often advertised prize-essay of M. C. H. Schultz * 



* Extv. des Mem. de l'Acad. des Sciences, torn. vii. des savants Strangers. 

 1839. 



