F 



iirj.^ 



tatcs 



THE BEGINNINGS OF LIFE. 



51 



°"y a. 



in ^^. one another in that particular mode of collocation which 



It will be belongs to, and constitutes, the molecule in question. 



1 



pound 



substj; 



The phenomena of allotropism, as we have previously 



reat 



^o^ccular rw. hinted, and various other considerations, tend to show 



atomic 

 the 



r 



com 



t- 



er to the 



.mat; 

 inut 



that even simple bodies — such as phosphorus, sulphur, 



and the metallic elements — are made up of molecules 



to \vl ■ li 7 composed of similar atoms existing in a definite number 



I K 1- ^^^ grouping in each allotropic state or separate sub- 



stance. An alteration of the number or grouping of 

 the atoms in the molecules, or of both, seems to be the 

 only way of accounting for the wholly different proper- 

 ties and crystalline form of one and the same sub- 

 stance, such as sulphur, under the influence of different 



thcrcforCj up: physical conditions. And thus vanishes the difference 



cms in the 1. between simple or elementary, and compound bodies. 



cule can bee They are all made up of molecules^ only those of 



properties wlui 

 and oxygen: 



iroperties oft the simple substances are aggregates of similar atoms, 

 utual influence whilst those of compound substances are aggregates of 



dissimilar atoms. 



Different compound substances vary immensely in 



their degree of complexity. Some, such as ordinary 



IS belonging 



totli 



colour and are t* 

 ss by molecular » 



t— into the opaf acids or bases, are aggregates of simply complex mole- 



■e kno\\'n 



by 



the; 



is much moref 



cules; others are aggregates of doubly complex mole- 



+ 



cules — that is to say, two simply complex molecules 



. .1 jji rhoi^' combine to form a doubly complex molecule, and_, 

 ^ 'ly oxidize*'' when aggregated together, these include, amongst other 

 Mire The se^^^ . compounds, a very common class known as salts ^ 



oine 



has 



,ho\vT 





le one 



irtial- 



foriB 



^ As a general rule, it may be said that decomposition follows the 

 into" reverse order. The larger molecules separate most easily; and the 



