V. S. Syrokomsky. Application of Rare Elements in Industry. Petrograd, 1919. Scientific Chemical-Technical Publishing House. 34 pp.

The author of this interesting brochure set himself the goal of gathering information on the industrial application of rare elements, which until quite recently had been only an object of scientific investigation by chemists. The fact is that in recent times industry has shown a clearly expressed tendency toward the practical use of such elements, since certain properties of theirs in the free state, as well as in the form of chemical compounds and alloys, are of special technical interest.

In its time, in the 1870s of the last century, much stir was caused by Auer von Welsbach’s invention of gas-mantle lamps, whose “mantles” contained two elements from the group of the rare earths, thorium and cerium—both in the form of oxides. The broad use of gas-mantle lighting created an extensive field of industry, and the rare earths, distinguished by the difficulty of separating them from one another, having become an object of special attention for researchers and industrialists, ceased to be as rare and as little accessible a material as before.

In recent times, alloys of cerium and other rare-earth elements with iron have found broad application for the manufacture of pyrophoric “flints” in lighters. A number of other more or less rare elements have likewise found various practical applications. Of very great importance is the use of molybdenum, tungsten, and vanadium for producing special grades of steel (tool steel, armor steel, etc.). The admixture of these elements imparts to steel special and very valuable properties, for example hardness and the ability, without alteration of physical properties, to withstand the action of high temperature, etc. Tantalum and especially tungsten, owing to their infusibility, have found application in the manufacture of electric incandescent lamps. The use of radium in medicine is universally known. The rarity and high cost of radium have made its extraction from ores a matter of great attention for industrialists.

From these examples it is evident what interest attaches to the question raised by V. S. Syrokomsky in his brochure, the appearance of which can only be welcomed.

L. Chugaev.