8 



As a whole, the old symbols, representing combining proportions, are ap- 

 plicable to neither column of atomic weights. Fewer changes are required by 

 adopting the weights of the first column ; yet the advantages derived from 

 estimating H rz 1 are so obvious, that the symbols used in the remainder of 

 this paper will represent the numbers in the second column. Those having the 

 old value will be denoted by the usual letters, and symbols of doubled value 

 by full-faced type. 



A complete series of known oxides of several metals (excluding hydrates) 

 are here presented, for the purpose of comparing the old and new system as 

 to brevity and precision. 



1. Protoxide of iron (Ferrous oxide), FeO : Ferramat. 

 Sesquioxide or Peroxide of iron (Ferric oxide), Fe 2 3 : F err emit. 



INTERMEDIATE OXIDES, 



Black or Magnetic oxide of iron (Ferroso-ferric oxide), Fe 3 4 : Ferrimot. 



A nameless oxide of iron (auct. BERTHIER & GLASSON), 



4 FeO F 2 3 = Fe 6 7 : Ferreameet. 



Scale oxide of iron (inner layer), 6 Fe Fe 2 3 = Fc 8 9 : Ferreimeot. 



The name of the latter, expres.-ing the supposed rational formula, is Ferreameat Ferremit. 



2. Protoxide of manganese (Manganons oxide), MnO : Manamat. 

 Red oxide of manganese (Manganoso-manganic oxide), Mii 3 4 : Manimot. 

 Sesquioxide of manganese (Manganic oxide), Mii 2 0a : Manemit. 

 Peroxide of manganese (Dioxide of M.) ; Mn0 2 : Manamet. 



3. The Chromium atom, properly Chromam, may be contracted to 



Chram; which is especially convenient in denoting chromates. 



Protoxide of chromium (Chromous oxide), CrO : Chramat. 



Magnetic oxide of chrome (Chromoso-chromic oxide), Cr 3 4 : Chrimot. 



Sesquioxide of chromium (Chromic oxide), Cr 2 3 : Chremit. 



Monochromate of Sesquioxide of chromium, Cr 3 6 : Chrimeat. 



Bichromate of Sesquioxide of chromium, Cr 4 9 : Chromeot. 



Neutral chromate of Sesquioxide of chromium, Cr 5 0i 2 : Chrumoit. 



Acid chromate of Sesquioxide of chromium, Cr 6 0i 6 : Chreamyut. 



Chromic acid Cr0 3 : Chramii. 



Including hydrates, the oxides of metals, metalloids and organic radicals now 

 known may be estimated in round numbers at 400. The following oxides of a 

 halogen are adduced to show the inadequacy of the old nomenclature in de- 

 fining the higher combining ratios of only two elements : 



lodic anhydride, I 2 5 , evut ; Hypoiodic acid, I 2 4 , evot ; Intermediate oxide (auct. 

 K.EMMERER), I 6 0i 3 , eavyit ; Subhypoiodic acid (anct. MILLON), Ii 0i 9 , euvyeot. 



A few brief observations will perhaps aid in apprehending the purport of 

 numerous new combinations, illustrating the doctrine of types and substitutions. 



1. An atom has a definite maximum power of holding other atoms in chemi- 

 cal union. The normal quanti valence or highest saturating capacity of an atom, 

 that is, its so-called atomicity, decreases as it is duplicated and condensed. 



2. Chlorad is ranked in the class of elements having the lowest saturating 

 power : therefore ad may be taken as the unit of measurement, and thus words 

 already in use in this connection are made peculiarly appropriate ; for ex- 

 ample, hydral is a monad, oxat is a dyad, nitran is a triad (often a pentad), 

 carbar is a tetrad, phosap is a pentad and often a triad. Carber, ferrem, alem, 

 chromem, and other DOUBLE-ATOMS forming sesquioxides, behave like hexads, 

 while manam appears to be a heptad. Arsam, bisam and stibam are either 

 triads or pentads. 



3. A molecule is a complete chemical structure, capable of existing in a 



