250       Dr.  C.  R.  A.  Wright  on  the  Relations  between  the 
what  analogous  fashion.  Thus  by  comparing  formulas  which  are 
analogous,  but  differ  in  the  value  of  the  suffixes,  it  is  noticed  that 
a  difference  in  the  boiling-point  occurs  precisely  proportionate  to 
the  alterations  in  the  suffix-values  multiplied  respectively  by 
certain  numbers  attributed  to  carbon,  hydrogen,  oxygen,  &c, 
the  values  of  these  numbers  frequently  depending  on  the  class 
of  compound  examined*. 
A  somewhat  similar  circumstance  occurs  as  regards  the  melt- 
ing-points of  bodies  of  analogous  formulae,  though  the  numerical 
connexions  do  not  appear  to  be  so  distinctly  marked. 
The  specific  heats  of  solid  substances  of  analogous  formulae 
are  also  frequently  found  to  be  inversely  proportionate  to  the 
sum  of  the  product  obtained  by  multiplyiug  the  combining  num- 
bers of  each  symbol  in  the  formula  by  its  suffix  and  adding 
together  the  products. 
16.  When  the  elementary  symbols  are  arranged  in  the  order 
of  their  combining  numbers  fixed  by  the  foregoing  considerations, 
they  are  found  to  succeed  one  another  in  a  remarkable  sequence 
as  regards  their  chemical  analogies,  forming  sets  of  (usually)  8 
numbers  each  so  arranged  that  the  1st,  2nd,  3rd, . . .  members 
of  each  set  exhibit  considerable  analogy f. 
General  formula  of  oxygen  compound. 
R20.     R202=RO.     R203. 
R204=R02.    R205.    R206  =  R03.  R2  O7.  R208=R04 
General  formula  of  hydrogen  compound. 
RH4. 
RHS 
RH2 
RH. 
H  =  l 
Li=7 
Na=23 
K=39 
Cu=63 
Rb=85 
Ag=108 
Cs=133 
Au=199 
Be  =  9-4 
Mg  =  24 
Ca=40 
Zn=65 
Sr=87 
Cd=112 
Ba=137 
Hg=200 
B  =  ll 
Al=27-3 
Yt=88  ? 
In  =  113 
Di=138? 
Er=l78? 
Tl=204 
C  =  12 
Si  =  28 
Ti  =  48 
Zr  =  90 
Sn  =  118 
Ce=140> 
La  =  180? 
Pb  =  207 
Th  =  231 
N  =  14 
P  =  31 
V=51 
As  =  75 
Nb  =  94 
Sb  =  122 
Ta=182 
Bi  =  208 
0=16 
S  =  32 
Cr=52 
Se=78 
Mo=96 
Te=125? 
W=184 
U  =  240 
F  =  19 
CI  =  355 
Mn  =  55 
Br  =  80 
1  =  127 
fFe  =56 
\  Co  =59 
LN    =59 
fRu  =104 
\  Rh  =104 
[Pdl=106 
fOs  =195 
\  lr    =197 
Pt  =198 
*  Kopp,  Ann.  der  Chem.und  Pharm.  vol.  xcvi.  pp.  2  &  330;  vol.  xcviii. 
pp.  267  &  367. 
t  Newland's  "Law  of  Octaves,"  Chemical  News,  vol.  xiii.  p.  113. 
Odling,  'Lectures/  passim.  Mendelejeff,  Ann.  der  Chem.  und  Pharm. 
(Supplement)  vol.  viii.  p.  133.  Zaengerle,  Deut.  Chem.  Ges.  Ber.  vol.  iv. 
p.  571. 
