4 rows

2 rows

1st leather Torpedo in water.

nearly same, but I believe not so strong as last.
very slight.

601] Sat. May 27 [1775] with 2nd leather Torpedo under water, 3 rows charged to 1 on electrom.*

Shock with one hand to one person seemed stronger, to another weaker than with both.

Communication being made with metals instead of the hands, no shock was felt, but when all the rows were charged to 3, Mr Ronayne felt a small shock.

With wooden Torpedo, 1 row to 11; shock passed across 27 links of heavy chain with light. It also passed across 4 links of small chain with light, but not across 6.

Without Torpedo, 5 + 1 + 2 to 1; shock passed with light through electrom., no candle in room; also with torp. charged as in trial.

On a former night in trying wooden Torp., charged I believe much the same as this time, no light was perceived, though Mr Hunter felt a shock, but very weak.

One candle in room, hid as well as possible behind screen.

With Gymnotus, all rows charged to 31.

Doubtful.

Dr Priestley and Mr Lane touching with 1 hand at same time, Dr Priestly felt shock extend to elbow.

A former night, 3 rows charged to 13, Mr N. thought the shock extended to elbow; no one else thought so.

Sat. May 27 [1775].

602] Old Torp. out of water 2B+ A (8·1)†, tried with metals, weak shock.

New torp. B+ A (4·6) as strong as former.

The old Torp. tried with one hand holding metal against bottom side, in other hand holding bright link.

row.

*

[Art. 419. The (artificial) Gymnotus is not elsewhere mentioned.] +[The numbers in brackets are the charge communicated to the battery or the See Art. 583.]

3A (3) no shock, with B (3.6) a very slight shock when torp. was just wetted, none else.

With long link, not bright, 3A, (3), sometimes felt it, not always; with 2A never.

With wire of same size bright without link, seemed not to feel it so well.

With small link not bright no shock with B+ A (4·6), but there was with B + 2A (5-6); with bright wire without link felt shock with B+ A (4.6), but not with B. (3-6).

With dirty link 2B+ A (8.1), sometimes a small shock, not always; with 2B+ 2A (9-1), certain.

603] Tried with Lane's electrom.; dirt unaltered.

604] It was tried whether distance on Lane's electrom. at which jars discharged was the same at the same separation of straw & pith ball electrom. whether number of jars was great or smallt.

This was tried first by laying small knob'd Lane on wire while jars were charging, and afterwards by charging jars, without Lane lying on wire, to a little greater and little less degree by electrom. than what it was before found that they discharged at; then touching them with Lane, I could not perceive that the number of jars made any difference.

It was tried by comparing 1 & 4 jars with straw el. at 2 and by comparing 1 and 7 rows of battery with pith balls at 1.

It was also tried whether the number of jars electrified affected the separation of straw el.: by connecting 4 jars to the wire & then withdrawing 2 of them. It was not found to be at all affected.

Tu. May 30 [1775].

605] Charge required to force el. through 4 links of small chain, and also through 2 loops of machine*, 5 links of chain in each loop.

Trial of charge required to pass through 4 links of chain.

2.6 sometimes passed, sometimes not.

1

3A

Do.

3B+C+2A = (9.2) commun. to 1 row, 2 passed through 2 loops, once missed, once did not pass through 3, never through 5.

R communicated to 7 rows= 20-6 was tried 3 times without ever passing through 3 rows.

Wed. May 31 [1775].

606] 1 jar was elect. and commun. to 1 row of battery, and shock taken without torpedo. There seemed a little difference in the strength of the shock according to which row it was communicated to, but hardly more than was observed at different times from the same row.

Result of exp. May 30.

607] By mean, quant. el. req. to give same shock with 7 rows is to that with 1: 18·3 : 11·5 :: 1·6 : 1†.

608] The 2nd leather Torp. was tried in sand wetted with salt water. The Torp. lay flat on sand and was covered by it all but pos. elect. parts & middle of back. With 3 rows charged to 11⁄2, felt a shock whether I laid bare hands on torp. & on sand 16 inc. dist. from nearest part of Do. or whether I touched torp. with metals. In latter case shock seemed much the same as shock 10 inch plate crown glass § received 91 through Lane's el. at inc. 1600

If I laid pieces of sole leather|| which had been

soaked in salt water for a week and then pressed between paper with hundred weight for

* [Arts. 433, 605.]
+ [Art. 422.]

S [Arts. 411, 430.]

[Arts. 406, 573, 610, and Note 31.]
# [Art. 423.]

day to drain out moisture on torp. and on sand, and received shock with metal that way, shock was about equal to that of 10 inc. plate with

61 Lane at 1600'

The torp. taken out of sand and tried with metals in usual way gave shock about equal to D° plate, Lane at 181.

Being tried in same manner with 1 row, shock was weaker than in sand through leathers, & with 2 rows stronger than without leathers.

The spe. gra. bottle with water which came from sand weighed 8.4.11. Th. at 69, so that the water with which it was moistened appears to be of right strength.

609] Bits of beech, wainscot & deal* about inch square were soaked in salt water for 3 or 4 days, then taken out and wiped and exposed to the air in dry room for about 6 hours.

The shock of the Torp. was received touching pos. el. part with metal and neg. with one of these bits, the end which touched the torp. and that part which I held in hand being bound round with tin foil.

With 6 rows elect. to 12, I felt slight shock through wainscot: dist. tinfoils 2 inc.

With Do charge through deal, tinfoils at 1 inc., none.

With 3 rows to 1; received shock through beech, tinfoils at 41 inc. dist., about as strong as with 1 rows when touched with metals on both sides.

With Do charge through 4 inches of dry deal dipt in salt water and tried the instant it was taken out, none.

Taking hold of tail in one hand & touching pos. side with metal, brisk shock. When touching neg. side with metal much slighter, the exper. tried with each pos. and each neg. part.

Mon. June 12 [1775].

610] Jar 1 elect. to 21 by pith el. seemed to give shock of same strength as B+ 2A comm. to whole battery; it was weaker than 2B and stronger than B commun. to D°, but as there is a good deal of difference between the sensations of the 2, it is not easy comparing them.

According to this exp. the numb. jars which el. should be divided amongst in order to produce given shock should be as the 27 power of quant. el., and therefore el. 2 jars should be comm. to 5 more in order to produce same shock as 1 jar t.