40 THE CHEMISTRY OF CREATION. 



two gases. These laws are the laws of chemical . 

 combination. 



Having thus alluded to the elements, to 

 their tendencies to combine together, and to 

 the results that would without doubt follow 

 were no controlling principles in existence to 

 direct, harmonize, or neutralize the contend- 

 ing powers, we may briefly mention the laws 

 which effect these objects, and by their simple 

 but beautiful adjustments, produce much of 

 that harmony which we behold in nature. Other 

 laws may be broken or rendered inoperative 

 by the force of circumstances ; but these laws 

 are fixed and unalterable. They are four in 

 number. 



1st. The same chemical compound (say water) 

 must always possess a definite and unalterable 

 constancy of composition. 



For example : If we took a glass-full of 

 water from a way-side brook in England, and 

 another from the bosom of the Ganges deep in 

 Hindostan, or a third from some mountain- 

 torrent of the Alps, and examined them each 

 chemically, of course taking care to distil 

 them separately so as to obtain the water free 

 from all earthy or other impurities, we should 

 find that the water in these three instances 

 had precisely the same composition; that is, 

 by weight, eight parts oxygen, and one hydro- 



