Evolution and Devolution of the Elements. 23 
nebulous stage of matter is the first of which we have any 
knowledge. The spectra of the very earliest nebula? consist 
o£ three lines only, their wave-lengths being 5007, 4959. and 
4862 t.m., and corresponding to hydrogen and two unknown 
elements. As a nebula grows more compact, two more lines 
appear with wave-lengths 4340 and 587G t.m. These are 
due to hydrogen and helium respectively. Consequently, we 
might well suppose that in the nebulous stage of matter there 
are four substances, the first two being unknown upon earth, 
the third being hydrogen, and the fourth, which apparently 
only exists in small quantities, being helium. It also seems 
probable that except these four, no other elements exist in the 
early nebula? ; and if this is the case, we are justified in 
assuming that hydrogen, the two unknown elements, and 
helium are the four original elements from which all the 
other elements form. To distinguish them from the others 
we will term them protons. 
Before specifying which elements these four protons pro- 
duce, it will be as well to indicate as briefly as possible the 
manner by which we consider that one element gives rise to 
another. 
We may assume that all matter at some period was in the 
form of corpuscles. By certain processes, a description of 
which we hope to give in a future paper, some of these 
corpuscles arranged themselves into stable integral systems,, 
these systems being the four protons. These protons in turn 
developed into other atoms. Each of these protons begins to 
collect round it more corpuscles, this condensation continuing 
until a stable system is formed, capable of separate existence. 
The assemblage round the central atom may be regarded as 
having certain properties, and a more or less definite shape. 
We do not propose to speculate at all on the nature of this 
assemblage, beyond saying that the particles are probably in 
rapid motion, and that the whole atom forms a stable system. 
We may, however, for convenience denote this assemblage by 
the term "ring." If the atoms were really built up of con- 
centric rings, all that we have to say would apply equally 
well, so that in order to imagine the appearance of an atom, 
we may actually look upon it as composed of a series of rings 
of varying shape and size, and in all that follows we shall 
speak as though this were its actual structure, for the sake of 
simplicity ; but it must be distinctly understood that we make 
no assumption as to its true form. We may here mention that 
the formation of successive elements is attended by the escape 
of a large quantity of energy, and that the systems are steadily 
progressing from a higher to a lower energy content. In 
