between the Equivalent Numbers of Elementary Bodies. 357 
metal itself, corresponds with those of the metals of the arsenic 
series, Viz. : 
Specif. Vol. 
Vanadic acid, VO, 26°5 
Arsenious acid, AsO, 26°6 
Antimonic oxyd, SbO, 25°9 
Bismuthic oxyd, BiO, 25°9* 28°4 
They also point out the fact that vanadinite (vanadinbleierz) is 
isomorphous with the analogous compounds of the arsenic series, 
mimetene (kampylit) and pyromorphite. Professor Mallet has 
shown that reasons can be given for classifying osmium also in 
the arsenic series.t 
_Again, commencing with gold we obtain the following succes- 
sion of numbers. 
Differences, 
8x11! 196 Gold ap Lg 
108 Silver =108 
: 1100 Mercury =100 
: 92 Tungsten a= Un 
nats 64 Tellurium = 64 
. PORE Se. ‘Siete Cadmium —=56 
: {48 Molybdenum = 48 
: 40 Selenium = 40 
. BD ise suse eee Zinc =826 
“a t 16 Sulphur ca 
: 8 Oxygen aa, OB 
Tn an din the Memoirs of the Am. 
A Carn oy Pe lat acca: of Harvard Univer: 
ies 
By giving fixed values to a andd i iclss expressions pH 
obtai , Ziving rise to series by the changes in the value of = 
Yaiahe 2 These particular series were characterized by the 
Value of d, which in aifferent whic became ee, 3, 4, 5, 
+ Boullay geile ‘Am. Jour. Science, xxix, 
ad Me the at wt, of Zi whieh may be taken mie e add 16=2X8, we ce 23 
ate ee ey sition of 16 gives very nearly the at wt. of 
