Silex (silicium combined with oxygen) is contained in the hair and in some of the secretions.
These are the signs for the atomic weight of lead, and of silicium.
The two elements to be avoided by the founder are silicium and sulphur.
silicium has been discovered combined with iron to the extent of 3-1/2 per cent.
These zoophytes extract from the sea water the lime and silicium which are found there in the state of soluble salts.
Avoid sand crucibles, as silicium may be reduced and absorbed by the aluminum, inducing brittleness.
Of these, silicium is the most usual, and there is probably no cast iron that does not contain a portion of it.