Sabbah Abu Halima has very deep burns on her arm and leg. The doctors treating her at Gaza's Shifa hospital say they were caused by the Israeli army's white phosphorus incendiary shells.
They showed samples of the dark brown substance in plastic bags, emitting an unpleasant, chemical odour.
"It starts to smoke if you let the air get to it," said consultant surgeon Sobhi Skaik.
They also have photographs of burn wounds shortly after admission and their first, unsuccessful treatments, which failed to prevent the chemical burning down into the muscles.
Shifa doctors said they had about 10 cases of severe phosphorus burns suffered during Israel's three-week assault on the Gaza Strip.
"Most were moved to the Egyptian border then on to hospitals in Egypt or Saudi Arabia. We don't actually know where they are right now," said Skaik.
Israel's Haaretz daily on Wednesday reported that an army investigation into the use of phosphorus was focused on an incident in which 20 shells of it were fired into a populated area.
It said the shelling occurred in the northern Gaza town of Beit Lahiya. This is where Abu Halima was burned on Jan. 4 during a daytime attack that killed her husband and a son, the 45-year-old woman said.
"It was like bright stars falling, strong white light," she said, grimacing in pain in a hospital bed, with wounds heavily bandaged.
"When this woman was admitted the wounds were wrapped and closed. When we exposed them they started smoking. There was a chemical smell," said plastic surgeon Jalal Abdallah.
"It was not the smell typical of flame burns. They smell like charred meat. We did not know what this was at first. In the end we had to excise the burning flesh surgically."
Even after such treatment, several patients died because "they continued bleeding, although surgery was done well and vascular reconstruction was good", he said. "We don't know why."
Skaik said the burns were clinically proven to be caused by phosphorus but we need a laboratory study as well, to be objective.
According to Haaretz, the Israeli military fired a total of 200 white-phosphorous shells during its operation.
Some spent shells were shown to Reuters by a Palestinian salvaging possesions from the wreckage of his home in Jabalya, a suburb which was totally destroyed by Israeli forces. He also described the fiery substance falling "like stars" and said that "even putting it in water would not make it stop burning".
Israel prevented foreign journalists entering Gaza during the atttack.
Israel killed 1,300 Palestinians with a quarter of children and also wounded 5300 according to human rights groups.
Most of the cases in the rundown and overworked Shifa hospital are people wounded by more conventional weapons.
A collection of burst Israeli tank shells, and rocket fragments lie bagged and tagged in one office of the hospital.
Reporters watching Israel's attack from vantage points across the border saw the incendiaries bursting daily, some three or four hundred metres (1,000 feet) above the city.
They exploded in a big puff of white smoke, spraying large, brightly burning sparks over a wide area, like a jellyfish trailing burning tentacles over the rooftops.
International law forbids white-phosphorus use within concentrations of civilians.
Last Mod: 22 Ocak 2009, 17:24
Medical officials in Gaza reported during the Israeli offensive that two Palestinian children were killed and 14 people suffered severe burns on Jan. 17 when Israeli shells landed in a U.N.-run school in the Beit Lahiya area.
Haaretz said a brigade of paratroop reservists fired about 20 white-phosphorous shells into the built-up area. Amnesty International called for probe of Israeli war crimes over its use of these munitions in heavily populated areas.