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It can only be said that these impurities, as far as we are aware, increase the fusibility of iron, and that in an oxidizing flame oxidation becomes more excessive as the point of fusion approaches.

A writer in the Athenæum, in speaking of the expense of marble and bronze statues, which limits the possession of works of high art to the wealthy, calls attention to the fact that lead possesses every requisite for the casting of statues which bronze possesses, while it excels that costly material in two very important particulars—cheapness, and fusibility at a low temperature.

As a rule the iron meteorites are covered with pittings or thumb marks, due probably to the resistance and impact of the little columns of air which impede its progress, together with the unequal condition and fusibility of their surface material.

This is a kind of hard porcelain made from a mixture of kaolin and felspar, in which the degree of hardness or fusibility is regulated by the proportion of one material towards the other.

Of course, similar biscuits may be made by more complicated receipts, but the principle is always the same, viz. the taking advantage of the fusibility of felspar or Cornish stone, to secure the required amount of transparency.