THE ASH OF PLANTS. 163 
ysed the ashes of several plants, cultivated in a poor soil, 
with the addition of various mineral fertilizers, The in- 
fluence of the added substances on the composition of the 
plant is very striking. The following figures comprise 
his results on the ash of buckwheat straw, which grew on 
the unmanured soil, and on the same, after application of 
the substances specified below: 
A 2 3 4 5 6 
Unma- Chloride Nitrate Carbonate Sulphate Carbonate 
of of of. ef of 
nured. Ui Pp ti 9 lime. 
Potash vecevsavesees 2% 31.7 21.6 39.6 40.5 28.2 23.9 
Chloride of potassium. 7.4 26.9 0.8 8.1 6.9 9.7% 
Chloride of sodium.... 4.6 3.0 3.2 3.8 3.4 1.% 
TAG cua ceneradannnes 15.7 14.0 12.8 11.6 14.1 18.6 
Magnesia.............- 1.7% 1.9 3.3 1.4 4.% 4.2 
Sulphuric acid......... 4.7 2.8 2.7 4.3 t1 3.5 
Phosphoric acid. - 10.3 9.5 6.5 8.9 10.9 10.0 
Carbonic acid.. - 20.4 16.1 27.1 22.2 20.0 28.2 
BIUCR csecaxaas er 3.6 4.2 4.2 4.2 4.8 5.2 
| 
| 
| 
| 
ie 
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100.0 100.0 100.0 100.0 100.0 ~~ 100.0 
It is seen from these figures that all the applications 
employed in this experiment exerted a manifest influence, 
and, in general, the substance added, or at least one of its 
ingredients, is found in the plant in increased quantity. 
In 2, chlorine, but not sodium; in 3 and 4, potash; in 
5, sulphuric acid and magnesia, and in 6, lime, are present 
in larger proportion than in the ash from the unmanured. 
soil. 
6. What is the Normal Composition of the Ash of a 
Plant? Jt is evident from the foregoing facts and consid- 
erations that to pronounce upon the normal composition 
of the ash ofa plant, or, in other words, to ascertain what 
ash-ingredients and what proportions of them are proper 
to any species of plant or to any of its parts, is a matter 
of much difficulty and uncertainty. 
The best that can be done is to adopt the average of a 
great number of trustworthy analyses as the approximate 
expression of ash-composition. From such data, however, 
we are still unable to decide what are the absolutely es- 
