This was because Cameron had earlier shown specimens of the gold to George Hermann Bruhn, a German doctor and geologist whose services as an analyst were in great demand.
Then they showed him various specimens; he had been to very few lectures and, as soon as he was asked about things which he could not learn from books, he was floored.
A natural history museum on the site shows live specimens of local wildlife and fish.
It is likely that many of these were displayed at the Centennial Exposition in Philadelphia in 1876, as extant photos of the exhibit halls show similar specimens.
The picture on the right shows young specimens with quite vivid coloration.
Earth's Treasury shows specimens of rocks, minerals and gemstones behind glass in a dimly lit gallery.
He showed this and several other specimens of his work to botanical illustrator Francis Bauer, who encouraged him to present his "heliography" process to the Royal Society.
They show specimens of blood taken from guinea pigs at regular intervals after death.
Take a look at these slides showing specimens of Robling's blood.
The California astronomy exhibit displays the state's astronomical history through telescopes and artifacts, and the meteorite exhibit shows various ancient specimens.