482 



Prof. Silas W. Holman on 



Table IX. — Continued. 

 Exponential Equation. — Data minus Equation in Per Cent. 



Au-Hg 



15°. 



57°. 



100°. 



138°. 



181°. 



198°. 



217°. 



+0-01 



-0-12 



-006 



-0-06 



+009 



+0-12 



-0-80 



Ag-Hg 



-018 



+0-22 







+005 



-0-03 







-0-50 



Ni-Cu 



-0-26 



-0-16 







+007 



0-00 







-072 



Br-Ou 





-0-06 



-001 



+0-12 



+0-20 



-0'26 



-013 



Zn-Hg 





-030 



+0-02 



+0-14 



+010 



+0-65 



-0-04 



Pb-Ou 





-o-io 







-025 



+0-04 







000 



Cu x -Hg 



-0-19 



-0-27 



+0-01 





-0-03 







-0-25 



Co-Hg 





-005 



+001 



+6-48 



-001 





-1-00 



Pt^Ou 





-0-15 



+003 



-0-06 



+0-37 







-0-31 



Pt 2 -Cu 





-0-56 







-0-10 



-016 



+0-70 







Sn.-Ou 





-0-04 



+0-04 



-0-29 



+0-12 



+0-06 







Mg-Ou 





+0-18 







+015 



-052 



+017 







Al-Cu 





+0-16 







+0-12 



-0-24 



+0-18 







O. s.-Cu 





+0-07 



-001 



+008 







+0-05 



Average 



-016 



+0-08 



+0-01 



+0-03 



-002 



+014 



-027 



Logari 



thmic I 



]quatior 



l. — Date 



i minus 



Equatic 



n in Per Cent. 



Ul -Hg 



+2-3 



+1-5 







-0-40 







+0-50 



+080 



Discussion of the Deviations. 



Plots are given in the following diagram with temperatures 

 as abscissas and percentage deviations between the data and 

 the sundry equations as ordinates, i. e. 100 B/e where 8 = data- 

 equation. Inspection will show that with one exception (viz. 

 the logarithmic equation applied to the Barus data) these plots, 

 whether the equation is the ordinary parabolic, the Avenarius, 

 the Barus, the exponential, or the logarithmic, have the same 

 general form, which may be imperfectly described as follows. 

 If the equation be made to conform to the data at 0° C. 

 and at two higher points, a and b, then the deviation will be 

 of the negative sign from to a, positive from a to b, and 

 negative above b. The slight departures from this general 

 form are clearly due either to accidental errors, or to failure 

 to make the equation conform to the data at all three points, 

 or at suitable ones. The evidence is therefore conclusive 



