Intelligence and Miscellaneous Articles. 75 



ter-cresses, Lepidium sativum, L„ are among those which especially 

 contain much sulphur. 



As soils distant from volcanos do not contain perceptible traces of 

 sulphur, it appears to M. Vogel not impossible that plants, which 

 are much disposed to assimilate sulphur, may have the property of 

 deriving it from the decomposition of the sulphuric acid of sulphates. 

 M. Vogel, however, found that seeds placed in a soil perfectly free 

 from sulphur and sulphates, yielded plants which contained a notable 

 quantity of sulphur. 



The soil employed for this experiment consisted of coarsely pow- 

 dered white glass ; it was first strongly heated, but not fused, in a 

 crucible, and being afterwards washed with boiling water, not the 

 slightest trace of any sulphate could be detected. 



Seeds of water-cresses kept in a moist state were placed in this, 

 and when the plants were several inches in height, they were re- 

 moved with their roots ; after having washed the plants, the white 

 fibrous roots were cut off, and these as well as the plants were dried, 

 and on heating them in a retort, it was found that both of them 

 yielded considerably more sulphur than the seeds contained; the 

 expressed juice of the young plants cultivated in the powdered glass 

 also contained soluble sulphates. The seeds of water- cresses, sown 

 in coarsely powdered quartz, flint-glass, and very fine silica obtained 

 from silicated hydrofluoric acid, yielded similar results with respect to 

 sulphur and sulphates, though the plants did not flourish so well in 

 the last as in the two former substances. 



To obtain approximative results as to the quantity of sulphur in 

 the water-cress seeds and the plants which they yielded, the follow- 

 ing experiments were made : — The seed [100 grains ?] was heated to 

 redness in a retort, and the gases disengaged were received into a 

 solution of potash; acetate of lead was added to the alkaline liquor as 

 long as precipitation occurred. The precipitate was of a brownish 

 colour, and consisted of hydrate, carbonate and sulphuret of lead ; the 

 two former were dissolved by dilute nitric acid, and the sulphuret of 

 lead remained, which after washing and drying weighed 0'95 gr., 

 which indicated 0*129 gr. of sulphur. According to this experiment, 

 100 grs. of the seed contained 0'129 gr. of sulphur. 



The young plants obtained from the growth of 100 grains of the 

 seed were similarly treated ; their weight was 2040 grs.; they yielded 

 by the above- described processes 15" 1 grs. of sulphuret of lead, equi- 

 valent to 2"03 grs. of sulphur : consequently the dried plants con- 

 tained nearly fifteen times as much sulphur as the 100 grs. of seed 

 which produced them. 



Another experiment was made by projecting into a red-hot pla- 

 tina crucible small successive portions of a mixture of powdered 

 cress-leaves with nitrate and carbonate of potash. The residue, 

 heated in the crucible and treated with nitric acid, gave a con- 

 siderable precipitate with chloride of barium, but, on account of the 

 sulphate of potash which the plant contains, the quantity of sul- 

 phur cannot be accurately determined by this process, although in 

 general it is preferable to that above described ; 100 grs. of the 



