Having discovered that the natives have a mortal dread of the chameleon, one of which animals they had on board, they made good use of their knowledge. They had learned the market price of provisions, and determined to pay that and no more. When the traders, therefore, demanded a higher price and refused to leave the ship till it was paid, the chameleon was instantly brought out of the cabin, when the natives sprang overboard and made no further attempt to impose upon them. The sailors had also performed a gallant act. They were aroused one night by a fearful shriek, when they immediately pushed off in their boat, supposing, as was found to be the case, that a crocodile had caught a woman and was dragging her across a shallow bank. Before they reached her, the reptile snapped off her leg. They carried her on board, bandaged up her limb, bestowed Jack's usual remedy for all complaints, a glass of grog, on her, and carried her to a hut in the village. Next morning they found the bandages torn off and the poor creature left to die, their opinion being that it had been done by her master, to whom, as she had lost a leg, she would be of no further use, and he did not wish the expense of keeping her. CHAPTER TWENTY TWO. DR. LIVINGSTONE'S EXPEDITION TO EXPLORE THE ZAMBESI, CONTINUED. SETS OUT AGAIN--CHRISTMAS AT CHIMBA ISLAND--SENNA--DOWN THE RIVER TO CONGO--THE "PIONEER"--ARRIVAL OF BISHOP MACKENZIE--REACHES THE ROVUMA-- BACK AGAIN AND UP THE ZAMBESI TO THE SHIRE--LIBERATION OF A PARTY OF SLAVES--NEWS OF THE AJAWA STARTS FOR NYASSA--ENTERS THE LAKE-- DESCRIBED--A STORM ON THE NYASSA--SLAVERY--RETURNS TO THE ROVUMA--SETS OUT WITH BISHOP MACKENZIE FOR RUO--REACHES THE ZAMBESI, AND AFTERWARDS PROCEEDS TO THE GREAT LUABO--ARRIVAL OF MRS. LIVINGSTONE AND THE "LADY NYASSA"--BISHOP MACKENZIE'S DEATH--EXPLORES THE ROVUMA--AN ADVENTURE WITH THE NATIVES--VISITS JOHANNA IN THE "PIONEER"--STEAMS UP THE SHIRE-- EFFECTS OF THE SLAVE TRADE--MEETS MR. THORNTON--ATTACKED BY FEVER--MORE OF THE SLAVE TRADE--START FOR THE UPPER CATARACTS--DESPATCHES FROM ENGLAND--VISIT CHIA LAKELET--AN ARAB SLAVE-DHOW--LEAVES THE ZAMBESI, AND ARRIVES AT BOMBAY. Once more, on the 3rd of December, the leaky "Asthmatic" was got under way, but every day fresh misfortunes happened to her, till Rae declared: "She cannot be worse than she is, sir." He and his mate, Hutchings, had done their best to patch her up, but her condition was past their skill. On the morning of the 21st she grounded on a sandbank and filled. The river rising, all that was visible the next day was about six feet of her two masts. The property on board was, however, saved, and the expedition spent their Christmas of 1860 encamped on the island of Chimba.