Miller's lawyer has also been allowed a crack at him, which could be interesting. Miller is the witness who revealed many of the shocking details today, and was also the woman at the centre of the affair with Tudge and subsequent claims of bullying and physical abuse. I hope she nails the prick to the wall.

>is it because gold is so malleable but so is lead and lead is much more dense

Gold is much more dense than lead, at 19.3 vs 11.3 g/cm³, but the density of the metal isn't really a direct factor in Rutherford scattering in contrast to the atomic mass (more directly the atomic number, but this was prior to the discovery of the neutron) and atomic density. With gold being very close in atomic number to lead, and gold being more malleable and non-reactive than lead, and with gold foil more ubiquitous than lead foil, and with gold being more atomically dense than lead, there wouldn't have been an advantage to using lead over gold.

From Geiger's 1910 paper on the early experiments:

"Gold appeared to be the most suitable substance for such comparative measurements, since it can be obtained in very thin and uniform foils, and in addition its scattering power is higher than that of any other material available."

"Since thin and uniform sheets could only be obtained for gold, tin, silver, copper, and aluminium, the experiments were confined to these metals."

These and later experiments by Geiger and Marsden under the supervision of Rutherford ultimately showed that scattering per atom was proportional to the square of the atomic weight. That is, other materials were observed, but since gold was far more suitable and lead was very close in atomic weight to gold, it would not have yielded much more insight compared to lighter and more malleable materials. It's important to note that thin sheets and uniform thickness were important because the scattering was also observed as a function of the number of sheets used.

In fact, it appears that [lead was used in the early experiments] (https://royalsocietypublishing.org/doi/10.1098/rspa.1909.0054) but it was less effective than gold - this was speculated to be due to impurities in the lead but I believe atomic density would have played a role here, possibly also the relative difficulties in producing thin sheets of lead.