Department of Orthodontic Abstracts and Reviews

Edited by

DRS. EGON NEUSTADT AND JOSEPH D. EBY, NEW YORK CITY

All communications concerning further information about abstracted material and the accept- ance of articles or books for consideration in this department should be addressed to Dr. Egon

Neustadt, 133 East Fifty-Eighth Street, New York City.

Rustless Iron. Abstracted from: Ein Stiick Metallkunde, by Richard Schulz. Zeitschrift fiir Zahntechnik und Zahnheilkunde, May-June, 1934, Wien.

The introduction of stainless steel into dentistry has been well received on account of its outstanding physical and chemical qualities. But when we tie the shiny ligatures around our patient’s teeth, we should not forget that basic substance of sta.inless steel: rustless iron.

Chemically pure iron (Fe) has some qualit.ies which are not known to everybody. First of all, it does not rust. After many thousand years of en- deavor, modern chemistry has finally succeeded in producing iron which really is iron. This material does not possess that characteristic quality which hardly seems possible to dissociate from iron, namely, rusting.

This problem was first discussed between chemists and archeologists in a study of old Indian foundry works. Near Delhi, in India, there exist,s one of the most gigantic remnants of old Indian iron industry, the Kutub column. It is over 22 feet high and weighs more than 12,000 pounds. It is forged from one piece. From an inscription it appears that the column was made in the nint,h century B.C.

Despite its high age, not a t.race of rust can be seen on the Kutub column. This is more remarkable as the damp and warm climate would facilitate rust- ing. How can this phenomenon be explained?

An analysis of hhe iron used in the column showed that it was of a purit,y unattainable in the present-day foundry methods of iron production. Th c thought was conceived that the high purity of the iron caused its rustlessness. Rusting, therefore, is not a quality of iron itself, but of the impurities co37- tained in commercially produced iron.

Many years after this discovery, two American chemists succeeded in pro- ducing, through electrolyt,ical methods, iron of 99.9 per cent purity. This iron is very similar to platinum. It is used by jewelers for watch chains, stone mountings, and bracelets, The platinum color makes it suitable for these pur- poses, and also the fact that, even under the influence of skin perspiration, it

does not rust. I?. N.

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