234 TRAVELS ON THE RIO NEGRO. [November,
the pilot had been severely bitten by one some time before, and was afraid ; and so, instead of obeying me, they kept striking it with a thick stick, which only hastened its descent down the bank into the water, where, sinking to the bottom among dead trees, it was quite out of our power. As near as I could judge, the snake was fifteen or twenty feet long, and as thick as my thigh. At Sao Gabriel I saw also, on the rocks, asleep, one of the most deadly serpents of South America, the Surucucu {Lachesis mutus). It is very hand- somely marked with rich umber-brown, and armed with terrific poison-fangs, two on each side ; it is much dreaded, as its bite is said to be incurable.
On leaving Sao Gabriel I was again attacked with fever, and on arriving at Sao Joaquim I was completely laid up. My Indians took the opportunity to steal a quantity of the caxaca I had brought for preserving the fishes, and anything else they could lay their hands on; so I was glad, on the occasion of a slight remission of the fever, to pay their wages and send them off. After a few days, the violence of the fever abated, and I thought I was going to get over it very easily ; but such was not the case, for every alternate day I experienced a great depression, with disinclination to motion : this always followed a feverish night, in which I could not sleep. The next night I invariably slept well perspiring profusely, and, the succeeding day, was able to move about, and had a little appetite. The weakness and fever, however, increased, till I was again confined to my rede, — could eat nothing, and was so torpid and helpless, that Senhor L., who attended me, did not expect me to live. I could not speak intelligibly, and had not strength to write, or even to turn over in my hammock. A few days after this, I was attacked with severe ague, which recurred every two days. I took quinine for some time with- out any apparent effect, till, after nearly a fortnight, the fits ceased, and I only suffered from extreme emaciation and weakness. In a few days, however, the fits of ague returned, and now came every day. Their visits, thus frequent, were by no means agreeable ; as, what with the succeeding fever and perspiration, which lasted from before noon till night, I had little quiet repose. In this state I remained till the beginning of February, the ague continuing, but with diminished force ; and though with an increasing appetite, and eating heartily,
