158 Professor Haussmann on Metallurgic Crystallography. 
roding with acid its polished surface. But the octaedral for- 
mation of iron can be ascertained with greater certainty, by exa- 
mining some of those varieties which are produced by a metal- 
lurgical process. 
Jo. Hieron. Zanichellius was the first who published accurate 
observations upon the octaedral crystallisation of iron. For 
his information he was indebted to Valisnerius, formerly Profes- 
sor of Medicine in Pavia, to whom it had been suggested by 
some very skilful superintendant of metallic operations. 44 When 
he, 1 ' to use the words of Zanichellius, 44 had carefully melted a 
great quantity of iron-ore, and when, having finished his prepa- 
ration, the iron began again to return into a solid state, a por- 
tion of it swelled into a large and apparently hollow mass. Ha- 
ving broken this mass with the mallet, a most agreeable appear- 
ance was presented. The whole interior crust of this inflated 
mass was reduced into an innumerable number of pyramids, 
each pyramid being four-sided, and each of the planes which 
contained the pyramid having the appearance of being indented 
and grooved. 1 ' This description is illustrated by a figure. Ad- 
ditional notices of crystallised iron have been given by Grigno- 
nus, Pasumotus, and Romeus Insulanus. In latter times, 
Guyton de Morveau imagined that he had made new discove- 
ries concerning the crystallisation of iron and steel ; but he was 
unacquainted with the more complete and satisfactory observa- 
tions of Grignonus and others ; and what he has described is 
nothing more than the first principles of crystallization, pre- 
viously ascertained by alchymists, and denominated rete vulcani. 
Crude iron, called Frischeisen , which is produced in iron- 
furnaces, possesses the property of crystallisation. I have as- 
certained that the form of the crystals is octaedral. Grigno- 
nus has described and sketched cubic reguline iron. Pasumo- 
tus also procured from the cavities of a furnace belonging to a 
foundery a specimen of cubical iron, which, according to the 
description of Grignonus, was found connected with iron ami- 
anthus. Cubical crystallisations very frequently occur in sub- 
stances where the principal form is a regular octaedron. 
The crystallisation of malleable iron may frequently be 
ascertained, by examining the fracture of iron-rods. Iron 
appearing granular in its fracture, owes its texture to the in- 
tersected crystallisation, which is the more perfect, in proportion 
