680] [Same as Art. 368.] 681] By res. P. 5 [Art. 654] a globe of 12 inc. contains as much el. as a circle of 18.5*, therefore by Prop. XXIX. p = 13, therefore Charge of both plates 11 By 1st exp. 1772 [Art. 473] the proportions were 682] The charges of the following bodies are supposed to bear the following proportions to each other. and if charge cyl. is supposed to be to that of globe whose diam. = length cyl. ::: N. L. 2 length •998 their charge = 1·008. 1.006 This ratio approaches about 5 times nearer to the first proportion than the 2nd §. The area of the oblong is the same as that of the square, and their charges are very nearly the same. The charge of a square is to that of a circle whose diam. = side square as 1.153 to 1 ||. * [Note 35.] † [Note 21.] [Exp. vII., Art. 281. The numbers here are different. See Art. 478.] § [Note 12.] [This ratio is given in Art. 283 as 1·53 by a mistake of the Editor in copying, see Note 22.] 93 683] In exper. P. 11, 1772 [Art. 477], the large wire should contain about less el. than if its diam. was double the small ones. Allowing for this, the charges of the large wire at 36, 24 & 18 inc. dist. should be between the two following proportions: but I believe ought to approach about 5 times nearer to the former. The observed proportions are* 685] A shock is diminished very nearly the same, but if anything rather more, by passing through 9 tubes, 37 inches of which hold 3373 grains of, than through one tube, 37 inches of which hold 3480 grains of t. 686] A shock is as much diminished in passing through 6.8 inches of a tube, 37 inches of which hold 567 grains, as through 441 of one 37 inches of which hold 3480. So that resistance should seem as 1.03 power of velocity. 688] Resistance of sat. sol. S. S in 99 of distilled water is 39 times greater than that of the sat. sol. Resistance of distilled water is 18 times greater than that of sat. sol. in 99 of distilled water§. 689] Experiments in 1776 and 1777. N. B. It is not said what water the solutions were made with. By the comparison of salt in 999 with salt in 20,000, it should seem either that they were not made with distilled water, or that some mistake was made in the experiment. 690] In Jan. 1777, salt in 2999 conducted about 70 or 90 times better than some water distilled in the preceding summer, or about 25 or 50 times better than the distilled water used in the year 1776 *. Salt in 2999 conducted about 25 times better than salt in 150,000. 691] Salt in 69 conducts 1.97 times better in heat of 105° than in that of 58°. The proportion of the resistance of sat. sol. and salt in 999 to each other seems not much altered by varying heat from 50° to 95° ‡. 692] Salt in 150,000 seemed to conduct rather better than the same water deprived of air by boiling in the same vial in which it was kept, and cooled quick in water to prevent its absorbing much air. But the difference was not more than might arise from error of experiment §. 693] Distilled water impregnated with fixed air from oil of vitriol and marble conducted 2 times better than the same water deprived of its air by boiling. 694] Conducting power of other saline solutions compared with that of salt in 29 of water T. N. B. The solutions of the neutral salts were all of such strength that the acid in them was equiv. to that in salt in 29. The f. alk. also was equiv. to that in salt in 29, but the acids were equiv. to that in salt in 59. Salt in 20,000 conducts about 7 times better than distilled water. 696] Therefore the resistance of water with different quantities of salt in [it] are as follows †: |