106 



THE AMERICAN BOTANIST 



Leaf Skeletons. — In the IStli volume of this magazine 

 Ave gave several methods of making leaf skeletons. Another 

 method, Avhich may prove useful is mentioned in HorAvood's 

 "Practical Field Botany"". For this, you make up a solution as 

 folloAvs : 



Chloride of lime, 5 ounces. 

 AA^ashing soda, 6 ounces. 

 AA'ater, 2 ounces. 



The leaves of Avhich skeletons are to be made are to be 

 boiled in a strong solution of this until all but the veins are 

 removed. \Mien the green part of the leaf becomes softened 

 the leaf may be spread on a flat surface, such as a plate or pane 

 of glass and the soft parts Avashed out by a gentle stream of 

 Avater. Small and delicate leaves should be simph' soaked in 

 the solution. The skeletons may be dried betAveen sheets of 

 blotting paper. A set of leaf skeletons prepared in this Avay 

 is of more than passing interest. Formerly the only use of 

 such specimens Avas for making up Avinter boucpets. but they 

 are nOAv valued for Avork in botany. Xo other method shoAvs 

 the veins of plants so Avell. The specimens may be mounted 

 by gluing them to a piece of black cardboard and protected 

 from injury by a thin sheet of glass fastened to the cardboard 

 by gummed paper such as that used in making lantern slides. 

 If mounted betAveen tAvo sheets of glass in this Avay. they may 

 be readily examined by holding up to the light. 



Potassium and Plants. — The agricultural texts tell us 

 that the three elements needed by plants that are likely to be 

 lacking in ordinary soils are nitrogen, phosphorous and potash. 

 At present, the member of this trio most difficult to obtain is 

 potassium or potash. Almost the entire Avorld's supply comes 

 from Germany and as a result of the European Avar, our sup- 

 ply has been greatly curtailed. Deposits of potash are rare 

 in this country though there are hopes that deposits of this 

 substance in our arid SouthAvest may ultimately prove suffic- 



