Viewing page 64 of 195

This transcription has been completed. Contact us with corrections.

[[page]]120[[/page]]
July 5th 1844

This experiment was repeated by using two jars, and the apparatus from France for a spark in water.  See figure on opposite page.  When the foil was wet, and but partially submerged, the light on the foil was very distinct, but when the water was gradually increased, the effect was less and less, and when the water in the basin of india rubber stood at the depth of half an inch over the foil, no light was observed.

The same experiment was tried with 8 jars, the small [[?]] battery, but the effect did not appear greater than with two jars, and indeed it appeared less.  The intensity was less, and the effect appeared to depend in some degree on the intensity.

I think it probable that the effect is due to the distribution of the electricity towards the surface, and the bad conduction of the water.

For a notice of a paper on the spreading of oil on water, see bundle of scraps in my drawer under book case.

See note in the Proceedings of Polytec Inst. on the relative attraction of different liquids.

The compressibility of ice appears to be very little different from that of water, the true distinction between liquids and solids in the lateral adhesion which probably depends on the lateral adhesive.
Quarterly Rev 1812 p32.
[[end page]]
[[start page]]
Sept 28th Saturday    121
[[image - sketch of hemispherical bubble]]
 In a conversation with Mr Dean of Vermont yesterday, he suggested the idea that the bubble of soap water was not perfectly hemispherical, to determine this I measured several bubbles this morning in altitude and radius, and found the two to be equal. The measurement was not made with great care, but the difference from a semicircle could not be much. (Make the measurement again by cutting out a piece of card in the form of a semicircle. )
[[image - sketch of a bubble near the edge of a plate]] I observed today that when a bubble was thrown on a plate and pushed to the one side, it moved until it came on the edge, altering its shape from that of a hemisphere.
This effect I reffered after some study, to the action of the capillarity, the sides of the bubble are always perpendicular to the surface of the solid with which it is in contact.
[[image - a sketch of the apparatus described]] From the consideration of the theory of the soap bubble, I concluded that the contractile force of a small bubble is greater than that of a large one, and to test this by experiment, I made the above arrangement of a bent glass tube with a large phial (3 inches across) on one end, and a small phial of one inch in diameter on the other, the bottoms of the phials being removed.  The open end of the large glass being dipped into the soap water, and then the breath blown into the other phial, a large bubble was inflated on the large end, after this with a tobacco pipe, a small bubble was blown on the smaller end, the contractile force of the smaller one was shown to be greater than that of the larger by the diminution of the former, and the increase [[end page]]