MODERN SCIENCE. 187 



mentary matter that is, one antecedent form of matter 

 containing within itself the potentiality of all atomic weights, 

 would have evolved successively, say helium or hydrogen, 

 and then lithium next to it in simplicity of atomic weight, 

 and then glucinum, then boron, then carbon, and, gradually, 

 the rest of the seventy-two elements (which we call simple, but 

 which are in reality compounds), in the same manner that the 

 simplest life-germ, protoplasm, has evolved all organisms 

 so that the elements have been built up from one another 

 according to some general plan. Hydrogen was once 

 thought to have been the unit from which all elements were 

 derived; but this view is now put aside because, granting 

 the soundness of Mendelejeffs principle, the multiple of the 

 atomic weight of hydrogen does not account for twenty-six 

 (if not forty-five) known elements, and leaves too many gaps 

 in the series. It was calculated by Mr. Clarke that about 

 half the atomic weight of hydrogen would satisfactorily 

 account for the weights of all known elements, and of those 

 which would by-and-by be discovered to fill up the gaps 

 from hydrogen to uranium besides. The presence in the 

 sun of an element such as the one which would fulfil these 

 conditions has, it is thought, been detected. Helium, as 

 this element is called, is a much simpler one than hydrogen, 

 for it presents only one ray or line in the spectrum, and its 

 vapour possesses no absorbent power. It would then, if its 

 existence were confirmed, offer the conditions necessary to 

 allow of all the elements to fit in their places, and would 

 therefore be the basis required for the working of the Prout- 

 Mendelejeff law. Crookes thinks there may have been, 

 before helium or hydrogen came into being as such, an 

 antecedent form of matter protyle which evolved either 

 helium or hydrogen, or both in succession the rest coming 

 into existence in the course of cosmic events. That is his 

 hypothesis. "If he has grasped the key to the arrangement 

 he has gone far to unlock some of the deepest mysteries 

 of creation." This doctrine of chemical evolution was not 

 a conception of Crookes's. Sir Benjamin Brodie as early 

 as 1867, Prof. Stokes about the same time, Graham in '68, 

 and later Newlands, Mendelejefif, Prof. Victor Meyer, Dr. 



