56 THE CANADIAN NATURALIST. [Vol. vil. 



CHEMISTRY. 



Rubidium in Beetroot. — The average composition of the 



ash obtained from the beetroots of the North of France is the 



following : 



Potassium carbonate 30 per cent. 



Sodium carbonate 20 " << 



Potassium chloride 18 " <' 



Potassium sulphate 9 '' " 



Insoluble matter and moisture 23 " " 



Besides these substances, small quantities of iodine and brom- 

 ine, and of rubidium, are contained in the ash. The above sub- 

 stances may be separated by crystallization, or the potassium 

 salts may be utilized first by converting them into the chloride 

 and then into nitrate, by addition of sodium nitrate. After the 

 separation of the greater portion of these salts by evaporation, 

 &c., the rubidium may be precipitated from the diluted mother- 

 liquor by addition of dilute solution of platinic chloride, or better 

 by addition of a hot saturated solution of a potassio-platinic 

 chloride. The precipitate obtained may be freed from the* po- 

 tassium salt by washing with water, and then reduced in a 

 current of hydrogen. The author (E. Pfeifier) estimates that 

 ash froin the beetroot of the North of France contains about 

 1.75 grm. of rubidium chloride to the kilogram of ash. From 

 this it follows that 1 hectare of land yields about 255 grains of 

 rubidium chloride to every crop of beetroot. The rubidium 

 chloride contained a trace of caesium, but no lithium was found 

 in the ash. Tobacco from the same region contains potassium, 

 rubidium, and lithium and traces of sodium, whilst rape-seed 

 contains only potassium and sodium, but neither rubidium nor 

 lithium. — Abstract in Jour. " Chem. >Soc." 



Gold in Sea-water. — According to E. Sonstadt, the pres- 

 ence of gold in sea-water can readily be detected by several 

 methods, although occuring in the very minute proportion of less 

 than one grain to the ton. The solution of the gold is due to 

 the presence of iodine, which, as Sonstadt showed some time ago, 

 is liberated from the iodate of calcium existing in sea-water hy 

 the action of putrescible organic matter. The methods employed 



