256 Dr. Daubeny on the Degree of Selection exercised hy Plants, icith regard 



accuracy. 1124 grains of scarlet kidney-beans {Phaseolus inultijlorus) were 

 sown in a box containing about 290 lbs. of powdered sulphate of strontian, 

 which had been ascertained 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 alkaline 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 obtained. 



Now the aqueous solution represents the amount of alkali combined either 

 with the phosphoric or carbonic acids ; the solution in nitric acid without pre- 

 vious treatment, the earthy carbonates and phosphates * ; that in nitric acid, 

 after the action of an alkaline carbonate, the earthy sulphate, with that por- 



* The difference in the quantity of lime to be inferred from 100 of phosphate and 100 of carbonate 

 was only as 53 to 56. 



