646 
Proceedings of the Royal Irish Academy. 
HHH, that is to say, this curve excludes the possibility of any element, 
capable of combining with hydrogen, having a less atomic weight than 
that of hydrogen, including of course the so-called helium. 
This appears to me to be a striking confirmation of Dr. Eeynolds* 
contention that hydrogen is the last of a period of seven elements, and 
that the other six have no real existence. 
The equation of the asymptote is 
8m - + 5 = 0. 
(10) 
