Here's a remedy from the early 20th century.

When a recently slaughtered whale was towed ashore, a hole would be cut in the carcass and the rheumatic patient lowered inside, leaving just his or her head poking out.

It was believed that if the sufferer stayed there for about 30 hours, the resulting relief from aches and pains could last up to 12 months. The heat and gases created by putrefaction were thought to create a pain-relieving environment.

The bizarre treatment is revealed at a new exhibition that is part of Whale Season at the Australian National Maritime Museum.

The practice is thought to have started in the whaling town of Eden, on NSW's far south coast.

One claim is that the first man to try the cure stumbled drunk into a carcass before emerging sober and apparently free of his rheumatism hours later.

Michelle Linder, curator of the museum's Australian content, said: ''I don't know there was scientific evidence per se [to support the practice] but there was hearsay at the time that they felt better after being in the whale.

''It was done elsewhere but I don't think it was a really popular thing to do. It would have been an isolated thing to do.''

One museum exhibition, Amazing Whales - Evolution and Survival, has skeleton replicas dating back 50 million years that show how whales developed from primitive, hoofed land creatures and hippopotamus-like waterborne mammals.

Cetacean trivia in the exhibition reveal that a sperm whale can hold its breath for more than two hours, the 30-metre blue whale has no teeth and that toothed whales have a sixth sense and can analyse echoes bouncing off obstacles.

The museum's Whale Season includes an exhibition of life-size photography by Bryant Austin, in which visitors come face-to-face with giant underwater images of whales at sea. This exhibition opens on April 11. Another exhibition contains whale products including corsets, dominoes, soap, candles and umbrellas, but shows they remain threatened by pollution and illegal whaling.