separate state : that part of it which can unite with various monad radicals 

 known as the residue or remainder of a molecule being regarded as a broken 

 structure or imperfect body, may be called a torso. 



4. The atomicity of a torso, or of a radical containing one atom of an 

 element united to one or more atoms of another element, is equal to the dif- 

 ference between the normal saturating power of its components. The following 

 arc examples : 



COMPOUND MONADS : Ammonium. H 4 ^'" = olan or ilanal' ; Hydroxyl, H'O" = alt' ; 

 Amidogen, H 2 N'" = elan 1 ; Kitric oxide, ]X'"0 2 '' = anet ' ; 

 Cyanogen, i iv V = arn'. 



COMPOUND DYADS : Carbonyl (Carbonic oxide), C iv O"= arat or art" : 



Mouaraine. HN'"= a/an''; Methyleue, C iv H 2 = arel orach". 



COMPOUND TRIADS : Formene, C; V H = ar/"'; Phospil, P V 0" = apt'". 



5. The researches of KEKULE have shown that the same number of carbon 

 and hydrogen atoms, having different saturating powers, are related to different 

 hydrocarbon series; and the equivalence of such isomers may be determined 

 by the number of hydrogen atoms they contain. For example, glyceryl, 3 H 5 

 (echarl'"), having three less hydrogen atoms than the hydride of propyl (ichel), 

 3 H 8 , is a triad; while allyl, 3 H 5 (arechal 1 ). having one at-m of hydrogen less 

 than propylene, 3 H 6 (irlil") t is a monad. Thus also to the series of highest 

 saturation of carbon belongs acetylene, 2 H 2 (erel or erl iv ); and, having four 

 atoms of hydrogen less than the hydride of ethyl, C 2 H 6 (echel), it is a tetrad. 

 If two atoms of the monad bromine be added, the saturating power of the 

 compound will be diminished two degrees; therefore the bibromide of acety- 

 lene, C 2 H 2 Br 2 (erleb), is a dyad. The late brilliant elucidations of atomicity by 

 WURTZ have thrown light on many points, to which reference cannot now be 

 made. 



6. A complex hydrocarbon monad radical may be regarded as the combina- 

 tion of a monad with an even number of radicals or torsoes in equilibria. The 

 following are examples : 



Acetyl = (CO'' CH 2 ") + H = artachal'. 

 Propyl = (CH 2 " H 2 ") -f CH 3 ' = ichal 1 . 

 Butyl = (H 2 " CH 2 " H 2 " CH 2 ") + H = ochal 1 . 



7. GEPHARDT classified chemical compounds under four types, two of which, 

 the hydrogen and the hydrochloric-acid types, are molecules consisting of two 

 monads : one molecule should therefore be taken as the primal type, and the 

 other as a sub-type. The use of only three types would, at first sight, be com- 

 mended for its simplicity; yet the vast diversity of Nature's combinations 

 involves the necessity of many multiples, and the formation of mixed types as 

 proposed by ODLING, in which the saturating power of the several parts is 

 distinguished by the signs used in this paper. Valid arguments may be urged 

 in favor of using at least five types, in each of which, one-half the saturating 

 power expended to form the molecule is derived from a single atom. The 

 atom-holding power of one half being balanced by that of the other half of 

 each molecule, it is proposed to distinguish each type by the name expressing 

 the equivalence of one-half of it The following will show the value of the 

 new characters in typical expressions : 



2 



