The Principles of Chemistry, Volume II

By D. MENDELÉEFF TRANSLATED FROM THE RUSSIAN (SIXTH EDITION) BY GEORGE KAMENSKY, A.R.S.M. OF THE IMPERIAL MINT, ST PETERSBURG: MEMBER OF THE RUSSIAN PHYSICO-CHEMICAL SOCIETY EDITED BY T. A. LAWSON, B.Sc. Ph.D. EXAMINER IN COAL-TAR PRODUCTS TO THE CITY AND GUILDS OF LONDON INSTITUTE FELLOW OF THE INSTITUTE OF CHEMISTRY IN TWO VOLUMES VOLUME II. LONGMANS, GREEN, AND CO 39 PATERNOSTER ROW, LONDON NEW YORK AND BOMBAY 1897 All rights reserved
The periodic dependence of the composition of the simplest compounds and properties of the simple bodies upon the atomic weights of the elements.
Columns 1, 2, 3, and 4 give the molecular composition of the hydrogen and metallo-organic compounds, exhibiting the most characteristic forms assumed by the elements. The first column contains only those which correspond to the form RX 4 , the second column those of the form RX 3 , the third of the form RX 2 , and the fourth of the form RX, so that the periodicity stands out clearly (see Column 16).
Column 5 contains the symbols of all the more or less well-known elements, placed according to the order of the magnitude of their atomic weights.
Columns 7–14 contain the composition of the saline compounds of the elements, placed according to their forms, RX, RX 2 to RX 8 (in the 14 th column). If the element R has a metallic character like H, Li, Be, &c., then X represents Cl, NO 3 , ½ SO 4 , &c., haloid radicles, or (OH) if a perfect hydrate is formed (alkali, aqueous base), or ½ O, ½ S, &c. when an anhydrous oxide, sulphide, &c. is formed. For instance, NaCl, Mg(NO 3 ) 2 , Al 2 (SO 4 ) 3 , correspond to NaX, MgX 2 , and AlX 3 ; so also Na(OH), Mg(OH) 2 , Al(OH) 3 , Na 2 O, MgO, Al 2 O 3 , &c. But if the element, like C or N, be of a metalloid or acid character, X must be regarded as (OH) in the formation of hydrates; (OM) in the formation of salts, where M is the equivalent of a metal, ½ O in the formation of an anhydride, and Cl in the formation of a chloranhydride; and in this case ( i.e. in the acid compounds) Z is put in the place of X; for example, the formulæ COZ 2 , NO 2 Z, MNO 2 Z, FeO 2 Z 2 , and IZ 3 correspond to CO(NaO) 2 = Na 2 CO 3 , COCl 2 , CO 2 , NO 2 (NaO) = NaNO 3 , NO 2 Cl, NO 2 (OH) = HNO 3 ; MnO 3 (OK) = KMnO 4 , ICl, &c.