THE a,Β’ailable knowledge concerning the properties of metals and alloys and the dependence of these properties upon what we may call the life-history of these metals, including their pedigree, or preparation and composition, and conditions of birth, or their manufacture, is all too meagre, both in quantity and quality.
Thus Prof. H. Le Chatelier, who compiled the data on metallic alloys for the Table of Physical Constants recently published by the French Physical Society, prefaces his compilation with the following remarks :
" Concerning the physical properties of alloys, it is impossible to find numerical data worthy of any confidence. This comes from the fact that, on the one hand, experiments have been made by physicists too disdainful of chemical analysis, and, on the other hand, by chemists unfamiliar with physical measurements. It would be impossible in some cases to repeat, to within 5 Β° per cent., results which were measured nevertheless with a precision of one in a thousand, on account of lack of sufficient indications as to the composition of the alloy studied; again, several measurements made on alloys of exactly determined composition do not agree among themselves to io per cent. It is practically only for the melting-points of alloys that we possess somewhat accurate information."
This statement by Prof. Le Chatelier is by no means an exaggeration, and that such conditions as he describes with respect to the metallic alloys may exist appears to be due, in part at least, to the isolation and specialization of investigations, and to a lack of appreciation of the importance of the history of the materials * Presented for Dr. Burgess at a meeting of the Mining and Metallurgical Section held Thursday, March 30, t9~6, by Dr. Paul D. Merica. J9 20 GEORGE K. BURGESS. [J. F. I.
which are being studied. How many precise physical measurements, for example, have been made on material described merely as" iron," the results of which are oftentimes meaningless because of lack of a sufficient and necessary knowledge of chemical composition, mechanical treatment, and thermal history ? TABLE I.