34. Ash Elements In Plants

The ash elements of plants are important in this connection because they are the main source of the same elements of the human body. These may be held in plant tissue in three ways: in organic combinations, as the inorganic salts of the sap, and in crystals and incrustations. Outside of phosphorus and sulfur, comparatively little is known of the relations of the important ash elements to plant structure. The ash from different plants and parts of plants is by no megms uniform in composition and quantity, even in the same species or class of materials, although with the grains there is some degree of uniformity in this respect. Certain factors cause variations, such as species, stage of growth, fertility, the part of the plant, and changes due to manufacturing processes, and the variations which occur pertain not only to the amount of ash, but also to its composition. Different species of plants, and consequently different foods, are greatly unlike in their content of mineral matter. The figures below illustrate this fact, further confirmation of which may be had by consulting more extended tables: -

Table IX.The Mineral Compounds In Certain Vegetables And Grains

TABLE IX

The Mineral Compounds in Certain Vegetables and

Grains 1

(Per cent in the dry matter)

Potash

Soda

Lime

Magnesia

Iron Oxid

Phosphoric Acid

Sulfuric Acid

Silica

Chlorine

Potatoes . . .

2.27

0.11

0.10

0.19

.04

0.64

0.25

0.08

0.13

Turnips . . .

3.64

0.79

0.85

0.30

.06

1.02

0.90

0.15

0.41

Carrots . . .

2.02

1.16

0.62

0.24

.05

0.70

0.35

0.13

0.25

Radishes . . .

2.32

1.53

1.08

0.22

.21

0.78

0.47

0.07

0.66

Spinach . . .

2.73

5.81

1.96

1.05

.55

1.69

1.13

0.74

1.02

Parsnips . . .

2.63

0.07

0.55

0.27

.05

0.94

0.25

0.08

0.18

Winter wheat

0.61

0.04

0.06

0.24

.03

0.93

0.01

0.04

?

Oats (with hulls)

0.56

0.05

0.11

0.22

.04

0.80

0.06

1.22

0.03

Barley....

0.56

0.06

0.07

0.23

.03

0.92

0.05

0.68

0.03

Maize kernel. .

0.43

0.02

0.03

0.22

.01

0.66

0.01

0.03

0.01

Peas . . .

1.18

0.03

0.13

0.22

.02

0.98

0.09

0.02

0.04

Field beans . .

1.51

0.04

0.18

0.26

.02

1.41

0.12

0.02

0.06

1 Wolff's "Aschen Analysen."

We observe as we study the previous figures that phosphoric acid, potash, lime, and magnesia are the more prominent mineral compounds in plants, and it is with these that we find the most marked variations. The dry matter of vegetables and of peas and beans is much richer in potash and lime than is that of the cereal grains, and radishes and spinach have a relatively large amount of iron. Other differences occur. The amount and kind of mineral matter ingested in the food may be varied greatly by the selection of food materials.