166 On the Selecting Power of Plants 



the seeds of various plants, such as the garden raddish {Kapha- 

 nus sativus), the cabbage (Brassica nleracea), the garden bean 

 (Vicia Faba), hemp {Cannabis sativa). Sac, were sown in soils 

 containing various proportions of sulphate of strontian, with 

 or without manure, and, amongst the rest, one in which no other 

 ingredient except this earth, was present in any quantity. The 

 plants grew up, and when they had arrived at maturity, were 

 collected, burnt, and their ashes examined. No strontian, how- 

 ever, could be detected in any one of them, not even in that 

 where the matrix consisted almost wholly of the earth in ques- 

 tion. In 1831, the experiments were conducted with rather 

 more attention to accuracy. 1124 grains of scarlet kidney-beans 

 (Phaseolus multiflorus) were sown in a box containing about 

 290 lb. of powdered sulphate of strontian, which has been as- 

 certained to be free from alkaline matter, but to contain 2 per 

 cent, of carbonate of lime, and about ^ per cent, of alumina. 

 The box was placed in an open situation, exposed to sun and 

 rain ; and when the plants reared from these seeds had come to 

 maturity, they were cut down and burnt. An account was then 

 taken of the weight of the ashes remaining after the combustion 

 had been completed, and of the fixed principles obtained from 

 them, first, by lixiviation in water ; secondly, by digestion in 

 nitric acid; and, thirdly, by treating the remainder with an al- 

 kaline carbonate, and then, again, with the same acid as before 

 A similar process was gone through with the same quantity of 

 the kidney-beans as that of which the plants examined had been 

 the produce. 



The following will present a tabular view of the results ob- 

 tained . 



