313 



During the night the elimination of carbonic acid was considerably 

 diminished. 



Chemical relation of the alkalies contained in ashes op 

 PLANTS. — In two notes presented to the Academy of Sciences of Paris, 

 and published in Comptes-Rendus, MM. P. Champion and H. Pellet 

 have given results of a series of analyses tending to the establishment 

 of a law that a fixed relation exists between the quantities of the 

 alkalies present in the ashes of plants, depending upon the amount of 

 sulphuric acid with which they are capable of combining chemically, 

 and from the results of their labors it appears that to a limited extent 

 the alkalies are capable of substituting each other in the economy of 

 plant-growth. They have shown that while the quantity of sulphuric 

 acid necessary to saturate each of the alkalies separately may vary in 

 different samples, yet the sum of the quantities necessary to saturate 

 all of them is tolerably constant. This may be accepted as a general 

 rule, but is subject to some exceptions, depending upon the portion of 

 the plant examined and special conditions of culture. 



The following table, calculated from analyses of beets by different 

 analysts, will serve to illustrate the principle : 



Quantity of sulphuric acid corresponding to the potassa and soda 

 contained in 100 grams of ash 



Quantity of sulphuric acid corresponding to lime and magnesia con- 

 tained in 100 grams 



Total sulphuric acid 



Analyses hy — 



44.0 

 30.1 



56.5 

 17.5 



74.0 



oMc 



50.7 

 24.2 

 74.9 



From analyses of leaves of tobacco it appears that lime and potassa 

 have the property of partially replacing each other according to their 

 chemical equivalence. 



BOTANICAL iNOTES. 



By George Vasey, Botanist, 

 north AMERICAN MAPLES. 



Maples are very justly considered to be among the most valuable and 

 ornamental of forest-trees. They are natives of north temperate lati- 

 tudes, none being found in countries south of the equator, nor in the 

 torrid zone. They are confined to North America, Europe, and the tem- 

 perate parts of Asia. Two of the European species have been introduced 

 into cultivation to some extent in this country. These are the Norway 

 maple, Acer platanoides, and the sycamore maple, Acer pseudo-platanns. 

 A few other foreign species are occasionally found in public and private 

 gardens. But the maples of our own country furnish a very interesting 



