282 



On the Determination of Chemical Affinity. 



By interpolation from these values it is rendered evident that 

 whilst with acid of 40 grammes per 100 cubic centims. the 

 values of e for given currents were uniformly lower than those 

 for the same currents obtained with the same voltameter and 

 acid of 27*0 grammes per 100 cubic centims., the reverse holds 

 with acid of 11*4 grammes per 100 cubic centims. The fol- 

 lowing figures show that this is a fortiori true for acid of 

 1*0 and of 0*192 gramme per 100 cubic centims. 



Add containing 1*0 gramme H 2 S0 4 jt?£-r 100 cubic centims. — 



Voltameter No. 2 used. Value of specific resistance of acid of 



1 per cent, or sensibly 1 gramme per 100 cubic centims., 



8 x 22'1 

 22*1 (Kohlrausch), whence R= — ^ — =177 ohms. 



1 



Microwebers per 









Current. 



square centi- 

 metre. 



E. 



OR. 



e=E-0R. 



3-7 



046 



1-939 



•001 



1-938 



100 



1-25 



2-165 



•002 



2-163 



36-0 



4-5 



2-285 



•007 



2-278 



124-0 



15-5 



2-415 



•022 



2-393 



291-0 



36-4 



2-495 



•052 



2-443 



363-0 



45-4 



2-527 



•064 



2-463 



498-0 



62-2 



2-607 



•088 



2-519 



754-0 



94-2 



2-751 



•133 



2-618 



13 x 22*1 

 Voltameter No. 1 used. Value of It= — =-= — =192 ohms. 



I'D 





Microwebers per 









Current. 



square centi- 

 metre. 



E. 



CR. 



e=E-CR. 



7-8 



0-28 



1-993 



•002 



1-991 



17-3 



0-63 



2-114 



•003 



2-111 



27'2 



0-99 



2-141 



•005 



2-136 



48-1 



1-75 



2-193 



-009 



2-184 



88-7 



3-23 



2-253 



•017 



2-236 



149-3 



5-43 



2-294 



•029 



2-265 



324-3 



11-8 



2-387 



•063 



2-324 



4420 



161 



2-431 



•085 



2-346 



Just as with acid of 27*0 grammes per 100 cubic centims. 

 (§91 and 92), the two curves obtained with acid of 1 gramme 

 per 100 cubic centims. with voltameters Nos. 1 and 2 are sen- 

 sibly identical. 



18°=2*59 ohms; and acid of sp. gr. 1-1036 containing 15 per cent., 

 corresponding to 16-6 grammes per 100 cubic centims., gives sp. resistance 

 1-87 ohm; whence, by interpolation, acid of 11 -4 grammes per 100 cubic 

 centims. has sp. resistance 2-50 ohms. 



