Blood may be regarded as a complete fertilizer, as it contains not only nitrogen (from 2 1/2 to 5 per cent in a fresh state, and from 6 to 14 per cent in a dried state) but is also rich in all other plant foods, as may be seen by the following analysis of the ash: -

Per cent.

Sodium phosphate

16.77

Calcium and magnesium phosphates ...

4.19

Oxide and phosphate of iron ...

8.28

Sodium chloride (common salt)

59.34

Potassium chloride

612

Calcium chloride

3.85

Calcium sulphate (gypsum)

1.45

100.00

It will be observed that common salt constitutes more than half the weight of blood ash. When fresh blood can be obtained from slaughter houses it is best mixed with large quantities of soil and then allowed to "mature" in a heap until wanted for use. Dried blood is a more concentrated source of nitrogen than fresh blood, as water has been eliminated. It is a good fertilizer for all well-worked soils, and may be regarded as specially valuable for Potatoes, Cabbage crops, Vines, and fruit.