xx iv Contents 



RESISTANCE TO ELECTRICITY . . P. 311 

 From MS. No. 19 



ARTICLES 

 Comparison of conducting power of salt and fresh water, in the latter end of March 



and beginning of April, 1776. 

 Method of experiment . . . . . . . . . . ...616 



The experiments . . . . . . . . . . . . .617 



Six jars compared with one row. Experiments 618 



Examination whether salt in 69 conducts better when warm or when cold . . . 619 

 Examination whether the proportion which conducting power of sat. sol. and salt in 



999 bear to each other is altered by heat ........ 620 



Resistance of distilled water ........... 621 



Salt in 2999 and salt in 150,000 622 



Resistance of salt solutions ........... 623 



Comparison of water purged of air and plain water ....... 624 



Comparison of water impregnated with fixed air and plain water .... 625 



Resistance of solutions of other salts .......... 626 



Oil of vitriol, spirit of salt and f. alk. 627 



Experiments in January, 1781 ........... 628 



To find what power of the velocity the resistance is proportional to . . . . 629 



Salt solutions .............. 630 



Water and spirits of wine 631 



CALIBRATION OF TUBES 

 Jan. 1781. From MS. No. 19 



Tube 14 632 



Tubes 14, 15, 22, 23, 5, 17 633 



Tubes 12, 20 634 



Result 635 



RESISTANCE OF COPPER WIRE 

 From MS. No. 19 



Copper wire on glass reel 636 



Failure of former method ............ 637 



Barometer tubes as Leyden jars ........... 638 



Shock through wire plainly greater than shock received direct 639 



The same with jars i , 2 or 4 640 



Copper wire stretched by silk; sensation, sound and light of shock .... 641 



Wire wound round a slip of glass 642 



Wire from reel stretched 14 times round the garden ....... 643 



Copper wire silvered put on reel 644 



Comparison by sound 645 



Results 646 



RESULTS [OF COMPARISONS OF CHARGES] . P . 335 



From MS. No. 16 



Allowance for connecting wire ........... 647 



Square : globe : circle :: 1-125 : J 'S4 : J 648 



Compared results ............. 649 



Ditto. 650 



Circles 36, 18-5, 9-5 651 



