Arithmetical Relations between the Atomic Weights. 279 
In this table all of the above series are given, and the series, 
consisting of several members for each term, also, find their 
place. When we start from Be=9-4 and notice the following 
elements in the same = we find that the atomic weights con- 
tinually increase till =24 is reached; there are no more 
elements in the same ae the next highest being Al(=27-4) 
in the second line; the case is similar for this line, the atomic 
weights saeg ae? to Ca(=40), the eC stegiee being in the 
third lin e difference between the first and second lines 
is about ietiesn units; it becomes forty- aa oes for the second 
and third, and third and fourth; and is, finally, about ninety- 
three for the last term of the series, from Ti, Nb, Ta to Be, Al, 
Th. These three differences do not seem to be constant, but to 
increase with the values of the atomic weights; this is most 
apparent for ets largest ; vee smallest appears constant. 
It eem probable hat the lower terms of the series 
after iin gnceintis and as rahe as aluminum, should be wanting ; 
as, otherwis se, there would be two elements of equal atomic 
weights and differing largely in their chemical natures; whic 
last would be shown by their having to be placed in different 
parts of the table, which does not occur. From Ba(=187) to 
the next highest, T'a(= 182) i is forty-five units, about the value 
of the middle difference, If there were other elements be- 
tween these, there would be a similar anomaly to that just 
mentioned. The last serie of the series having the largest 
difference for their last terms, are T'ia(=182) to > Th(= 231); the 
increase in these is forty-nine units. It may be that Th(=281) 
is the largest atomic weight. 
One advantage of the table is its bringing elements of similar 
chemical and physical characters together. The metals and 
or a are separated almost completely. 
e are certain objections to the classification of some of 
the proche in the series in which they have been placed. It 
correspond in the members of the same series; this is best - 
shown in the case of the soluble oxides and sulphides; others 
are those of thallium and lead, and perhaps silver. The boun- 
daries in neither of these cases are to be considered sharp, and 
in both are obli 
here is a singular fact in regard to the specific gravities of 
the elements, when thus arranged. The speci ific aravities of 
the elements in the same line vary regularly and have one 
maximum and minimum; the maximum is in each case in the 
neighborhood of the members of the gold group, and the 
minimum among the metalloids; the speora of these two 
points are farther to the mens the lower the line; this is best 
seen for the minimum. The numbers above the symbols give 
the specific weights. Weak | is an exception. 
