10 
DE. A. MATTHIESSEN AND M. YON BOSE ON THE INELIIENCE OE 
TEe difference fbiinff Between tlie ' conducting powers of hard-drawn and ahhealedr whes 
■ r, ' Deduced to 0°. 
99-435 ■ ■' 
1O2-06& - 
6 . 
Hard di-awn 
Annealed, r 
Hard drawn 
Annealed . 
95-31 at 11-0 
97-83 at ll'O 
95-72 at 11-0 
98-02 at 11-0 
’ 99-a64' 
102-263 
These Tallies have been reduced to 0° as follows : take for instance the first, 93-00 at 
18'’-6. The mean of the six formulse obtained for copper (see Table XV.) is 
X=100-0-38701^+0-0009009^^; 
and calcnlatmg the conducting power for i8°-6 by this formula, we find it, equal to-_ 
93-114. 
Now ^^=0-99877; 
and if all the terms of the above formula be multiplied by this number; we "deduce a ' 
-formula by which the above value, can be reduced. All the reductions^ givun in- this--- 
paper of former determinations were made in this manner, using the formulie given in 
Table XV. The reductions to 0° in the Tables were made in a like manner, the only- 
difference being that the forihulie found for the respective wires were used instead of 
the mean. Taking the mean of all the values found for nopper, and using the mean for 
the formiilfe given in Table XV., we find as tho formula for correction of the con- 
ducting-power for temperature of 7 .. o , , , ’ . 
A hard-drawn wu’e X= 99-947 — 0-38&81^-l-0’0009004^^ 
An annealed wire A=102-213— ‘0-395’57if-l-0'0G09208^^. 
1 
The values given as first term in the formulse were found as follows : on referring 
to the paper* from which the conducting powers of copper were taken, it will be seen 
that each of them is the mean of three determinations. The reduced values therefore 
of 1 to 5, the mean of 6, hard drawn, and 7, hard drawn, and the mean of the first deter- 
minations of the three wires given in Table III., were added together, and the mean 
taken as the conducting power of a hard-drawn copper wire at 0°C. For the annealed, 
the per-centage differences of the values of 6, hard drawn and annealed, 7, ditto, and 
of the first determinations of the three wires in Table HI. and the annealed ones, were" 
added together, and the mean added to the value found for the hard-drawn wire (as a per- 
centage amount). All the formulae given as end-result with each metal have been 
constructed in this manner. 
Gold* 
Purified as described in the Philosophical Transactions, 1860, p. 175. Wires 1, 2, 
and 3 were of different preparations. The results obtained with these wires are given in 
Table IV. ^ 
Pliilosopliicd Transactions, 1860, 
