Page:Popular Science Monthly Volume 11.djvu/652

634 iron, on its surface, is transformed into the black oxide. Iron pipes protected by this process may be used instead of lead pipes for conveying water through houses. Iron for architectural uses may be made to resist the weather; the process may also be employed to protect cast-iron statues, which would thus be rendered as enduring as those of bronze.

Prof. Hebra on the Use of the Bath.—Prof. Hebra, of Vienna, dissents from the generally-received opinions as to the benefits of frequent resort to the bath. His views on this subject, as set forth at some length in the Boston Journal of Chemistry, are to the following effect: It is not true that frequent bathing is conducive to health, and harmless: millions of men take no baths of any kind, at most only washing the face and hands, and yet live to old age in good health. It cannot be proved that