i^ Ifog j&rmmts, (Sssap, Jtnb griiietos. [vn. 



I see no break in this series of steps in molecular 

 complication, and I am unable to understand why the 

 language which is applicable to any one term of the 

 series may not be used to any of the others. We think 

 fit to call different kinds of matter carbon, oxygen, 

 hydrogen, and nitrogen, and to speak of the various 

 powers and activities of these substances as the pro- 

 perties of the matter of which they are composed. 



When hydrogen and oxygen are mixed in a certain 

 proportion, and an electric spark is passed through them, 

 they disappear, and a quantity of water, equal in weight 

 to the sum of their weights, appears in their place. 

 There is not the slightest parity between the passive and 

 active powers of the waters and those of the oxygen and 

 hydrogen which have given rise to it. At 32 Fahrenheit, 

 and far below that temperature, oxygen and hydrogen 

 are elastic gaseous bodies, whose particles tend to rash 

 away from one another with great force. Water, at the 

 same temperature, is a strong though brittle solid, whose 

 particles tend to cohere into definite geometrical shapes, 

 and sometimes build up frosty imitations of the most 

 complex forms of vegetable foliage. 



Nevertheless we call these, and many other strange 

 phaenomena, the properties of the water, and we do not 

 hesitate to believe that, in some way or another, they 

 result from the properties of the component elements of 

 the water. We do not assume that a something called 

 "aquosity" entered into and took possession of the oxide 

 of hydrogen as soon as it was formed, and then guided 

 the aqueous particles to their places in the facets of the 

 crystal, or amongst the leaflets of the hoar-frost. On the 

 contrary, we live in the hope and in the faith that, by 

 the advance of molecular physics, we shall by and by be 

 able to see our way as clearly from the constituents of 

 water to the properties of water, as we are now able to 



