This, in fact, is the first proposition which we must all accept. No human being can add to or subtract a single property of any species of matter. To do so were, indeed, to create. For matter is an aggregate of properties; each species of matter is differentiated only by its properties, and could we alter one of these we should really turn it into different matter. It is true there are what are called allotropic forms, such as oxygen and ozone, the yellow and red phosphorus, the forms of sulphur as modified by heat, and a considerable number of organic compounds, and we can by certain arrangements turn the one into the other. But when we ask what allotropism is, we find that it is itself one of the properties (however obscure to us) of the matter we deal with. Oxygen would not be oxygen, but something else, if it had not the inherent property of becoming ozone under certain conditions. Given these conditions, and there is nothing we can do which will prevent the change occurring. If, as chemists believe, allotropism depends on the different arrangement of the ultimate atoms of matter, then the capacity of assuming two arrangements in its atoms is clearly one of the ultimate properties of that species of matter. It follows, then, that if a miracle were really a suspension of a physical law, or a change, temporary or permanent, of any property of matter, it would really be an act of creation--the creation of something having different properties from any matter that before existed. If iron were to float on water by suspension of the law of gravity, it would be in fact the creation of something having (at least for the time required) the physical and chemical properties of iron, but with a specific gravity less than water--and therefore something not iron. But, without creation, man has enormous power over Nature. He can, and daily does, overpower her laws, or seemingly make them work as he pleases. Despite the law of gravity, he ascends to the sky in a balloon; he makes water spring up in fountains; he makes vessels, weighing thousands of tons, float on the seas. Despite cohesion, he grinds rocks to powder; despite chemical affinity, he transmutes into myriads of different forms the few elements of which all matter consists; despite the resistless power of the thunderbolt, he tames electricity to be his servant or his harmless toy. With water and fire he moulds into shape mighty masses of metal; he shoots, at a sustained speed beyond that of birds, across valleys and through mountain ranges; he unites seas which continents had separated; there is nothing in the whole earth which he has not subdued, or does not hope to subdue, to his use. There is hardly a physical miracle which he does not feel he can, or may yet, perform.