between the Atomic Weights. 397 
by experiment, exceed slightly the theoretical numbers, and that 
where the affinities are the most intense, in fluorine, the deviation 
is the greatest. A similar fact may be observed in the atomic 
weights of the members of the Six Series. Arsenic has been 
thombic system. In the other aide, in which it may be 
obtained by sublimation at a low temperature, it crystallizes in 
regular octahedrons. ‘The other members of this series are prob- 
ably isodimorphs with arsenic. The ordinary condition of phos- 
phorus is its monometric modification, while the rhombic state 
seems to be the normal condition of arsenic, antimony, and bis- 
muth. Now the atomic weights of the last three are either equal 
to, or slightly exceed, the theoretical number, while that of the 
first falls short, perhaps even by a unit. Other facts, which also 
tend to show that the deviations are not matters of chance, may 
be found in the affiliations of the series. There are some ele- 
ments which seem to be most remarkably double-faced, having 
certain properties which connect them closely with one series, 
aa at the same time others which unite them nearly as closely 
to another. In such cases we find that the atomic weight either 
falls naturally into both series, or, not corresponding exactly with 
the theoretical number of the series to which the element prop- 
erly belongs, it inclines towards that of the other, and sometimes 
equals it. Such is the case with chromium, manganese, and 
gold, as will be seen by referring to the affiliations at the bottom 
of the Nine Series. These various facts force upon me the con- 
Viction, that this relation between the atomic weights is nota 
matter of chance, but that it was a part of the grand plan of the 
Framer of the universe, and that in the very deviations from the 
law, there will, hereafter, be found fresh evidence se the wisdom 
and. forethought of its Divine Author 
The general formule for the Eight Series are, 8:08 and 4+n8. 
The two nuclei correspond to two different sets of elements, or 
Sub-series, one pipetege asi of oxygen, sulphur, selenium, and tellu- 
rium, the other of molybdenum, vanadium, tungsten, and tanta- 
lum. ‘The sli weights of the first are all equal to 8+78; 
those of the second to 4+n8. The sub-series exhibit marked 
analogies, as well as certain differences. ‘They resemble each 
other chiefly in that the members of both form analogous acids 
with oxygen, while they differ in that though the members of the 
sub-series form compounds with hydrogen, those of the sec- 
Ond do not. The isomorphism of the members of each sub- 
Series among themselves, with the exception of vanadium, is 
Complete ; but there seems to be no proof of any isomorphism 
between t the sub-series. Johnston attempted to establish the iso-: 
™Morphism of chromic and molybdic acids from 4 red aiuaad of 
Stoop Szrtms, Vol. XVII, No, 51.—May, 1854. 
