514 
Proceedings of the Royal Society 
2. The production of heat. 
3. The decomposition of compound bodies. 
4. The volatilising of metals and other bodies by the sheer 
violence of its movements. 
5. The production of magnetic attraction. 
6. When transmitted through the animal frame it overpowers our 
natural voluntary movements, and produces spasmodic muscular 
contractions. 
To these different phenomena, for purposes of convenience, we 
give different names, but they are all the action of the same agent, 
viz., of power operating under different circumstances. 
We very much simplify and clear up our conceptions of nature 
when we attend to these two facts — first, that every change observed 
in the physical world, — whether effected by natural or by artificial 
means, and whether connected with animal or vegetable living 
organisms, or with inorganic matter, may be described as a move- 
ment either of physical bodies in mass, or as a movement of their 
constituent parts or atoms ; and second, that all these movements 
are effected by free an-atomic power, and by the transmission of 
it from one body to another. 
Mr Wyld further summed up his views thus — 
1. In the physical world we have a manifestation of power 
working uniformly according to physical law, i.e ., it is measured in 
amount, and it is fixed in its modes of action. 
2. Physical power we ascertain by an examination of physical 
phenomena is subject neither to augmentation nor to diminution. 
Were it not so the world would be entirely different from what we 
observe it to be. 
3. Power in all physical operations is transferred from one object 
to another, but is never lost. 
4. We may regard physical power as an immaterial agent, or we 
may be satisfied to consider it simply as a mode of action brought 
about by a cause unknown. But whether we view it as an agent or 
as an action, and in whatever way we may account for its existence, 
it is evident that as it conducts every change in the physical world, 
it must act according to invariable physical law. 
5. Physical power manifests itself in two distinct forms — namely, 
in the form of atomic bodies, which are discoverable by the senses, 
