52 MANURES. 
Of the dried plant without the seed, 5°359 grains, gave 
205 grains of gray ashes, which yielded on analysis: 
Silica........ Se OE eo segeucusaeemesas 85-854 gr anne 
Phosphorie Aci id OA Fi eer ae 18-245 
AWG scccsoasee ape Rianigcaaeupes aac eanuane oo va0 fe 
Magnesid...... sscccssecevscccececeseccnsoeass 2ST * 
Peroxides of Iron and Manganese... 3°03 a 
Palace. <.sccveceanevendtes ons se cetparepecoenuees 30°358 sé 
SOME, a czeseccnresersescs A adaek seeatb ea Tetons 14-534“ 
Chlorine .222...<: Beasts goths iasuebdeets oth ha Or em 
Sulphuric Acid.......2-scscccesssssnnveseees 11a. - ¥e 
Carbonic Acid......... BLES d titer pe a 6-560 * 
204-836 
| DR Re a a ey 164 
205-000 
The relative amounts of these constituents, it should be 
noted, are not proportioned to the degree of their im- 
portance respectively in the economy of the plant.* Those 
* “The Prince Salm Hortsmar, of Brunswick, has made the function 
of the mineral food of the plant the subject of a most extended and 
laborious investigation. In experiments with the oat, he found that 
when silica was absent from the soil, everything else being supplied, the 
plant remained smooth, pale, dwarfed, and prostrate. 
“Without lime the plant died in the second leaf. 
“ Without potash or soda it reached a height of about three re 
“Without magnesia it was very weak and prostrate. ‘ 
“Without phosphoric acid it remained very weak, but erect, and of a 
normal figure, bearing fruit. 
“Without sulphuric acid it was still weaker, was erect, and of normal 
figure, but without fruit. 
“Without iron it was very weak, pale, and disproportioned. 
“ Without manganese it did not attain perfect development, and bore 
but few flowers. 
“Other experiments proved that chlorine is essential to the growth of 
wheat.” 
He also “found that oats grown with the addition of fixed mineral 
matters (ash ingredients) only, gave four times the mass of vegetable 
matter that was obtained when these were withheld.”—Lectures on Ag. 
Chemistry at the Smithsonian Institution, by Prof. Samuel W. Johnson, 
(Smith. Rep. 1859, pp. 130-31.) 
