242 



THE CANADIAN NATURALIST. 



[Sept. 



Apatite, although of some importance to the manufacturer 

 of the clement phosphorus, and in the preparation of certain 

 varieties of porcelain, derives its chief interest from its 

 power, when used in conjunction with nitrogenous substances, 

 of restoring exhausted lands to their original fertihty, and of 

 increasing the value, for agricultural purposes, of such as 

 have always been, more or less, sterile and unproductive. 



Phosphoric acid is an essential element of all but the 

 lowest animal structures ; and the large quantities of phos- 

 phate of lime found in the chitinous tests of Lingula, as well 

 as in the shields of the Trilobitidse, prove that the element 

 phosphorus possessed, from the earliest geological epochs, 

 the same importance, in its relation to the animal kingdom, 

 as at the present day ; and, since the sole source of the 

 phosphorus in animal organisms is from the vegetable king- 

 dom, it is not surprizing to find that the element is equally 

 essential to the higher orders of plants, and, more especially 

 to those which are the most adapted to the wants of animals. 



The following Table, extracted, partly from the works of 

 S. W. Johnson, and in part derived from Emmons' Report, 

 on the Geology of North Carohna, exhibits this relation in a 

 very striking manner, and proves, moreover, that not only 

 the most nutritious plants, but also the most valuable portions 

 of the same species contain the highest percentages of phos- 

 phoric acid : — 



TABLE I. 

 Phosphoeic Acid in the Ashes of Plants. 



Series A — Edible Substances. 



p. 0.5 



per cent. 



Rice 53 



Eve 50 



Wheat.... 50 



Maize 45 



Oats 44 



Barley . . .39 



Beans 38 



Peas 33 



Turnips. ..13 

 Potatoes. .13 

 Clover ... .lb 

 Cabbage. .12 



p.o,, 



per cent. 



Rice straw .... 1 

 Rye straw. ... 4 

 "Wheat straw. . 3 

 Maize straw.. .17 



Oat straw 3 



Barley straw. . 3 

 Bean straw. . . 7 

 Pease straw. . . 5 

 Turnip tops. . . 9 

 Potatoe tops. . 8 



Beet root 8 



Meadow grass.. 8 



Series B — Miscellaneous substances. 



P.O., 



per cent. 



1 Leaves of Catawaba Grape. .18.3 



2 White Oak (Quercus Alba) 



Twigs 12-7 



3 Do. do. Wood.. 4.5 



4 Cotton (wool of) 11. G 



5 Tobacco . . . , 0.5 



7 Fibre of Flax 6.2 



Seaweed (average) 0.28 



Authorities : 

 Series I. Johnson. 

 Series II. 1-6 inch. Emmons. 

 7. Way. 



The phosphorus of plants appears, for the most part, to be 

 confined to the softer and more highly organized portions of 



