I 
48 THE AMAZON AND MADEIRA RIVERS. 
rovohitiou sliO’W'cd tliomsolves that filially separated the colony of Brazil 
frf)iii the mother-country, Portugal, there was a sort of Portuguese 
( Cayenne, or Lamhcssa, called Crato, on the Madeira, which had acquired 
a sad celebrity for its fevers. But it was not the Crato of to-dajq wliich, 
on the contrary, enjoys an unusually wholesome climate, in consequence 
of the extensive grassy plains in its vicinity. That place of exile was 
situated about thirty-six leagues higher up, at the mouth of the .Jammary, 
and it maintains its unhealthy repute to the present day. 
The plague gets more and more malignant and frequent as one 
approaches the region of the rapids, where a greater elevation and a 
rocky soil would lead one to suppose it less dangerous and less regular 
ill its ai)pearance. It has happened that Bolivian merchants descending 
the river have been in danger of losing everything by the sudden illness 
of all tliefr crew, and the death of some of them. The rest reached 
vSanto Antonio, the last rapid, ivith the greatest difficulty; but thence tlie 
descent can be effected, even with a sick crew, in case of need. 
On the extensive plains of Bolivia — ^between the Beni, Mamorc, 
Itonama, and Baures — which are completely submerged every yeai‘, and 
where the subsiding floods leave a great number of stagnant pools, whose 
water, brown with decomposed organic matter, is used even for drinking, 
intermittent fever.s, strange to say, are scarcely known. 'Within the 
last year only the first cases appeared at Exaltacion, on the Mamorc ; 
and the inexperienced inhabitants thought them some contagious disease 
brought from the Amazon or the Madeira. 
It is certain that, on the latter at least, the bad drinking-water, and 
the muddy floods issuing from the Beni at the beginning of the rainy 
season, are the chief causes of the ague ; but as some places, like Santo 
Antonio, are particularly afflicted bj^ it without any apparent reason, 
there must be another agent able to modify existing conditions, at least 
to a certain degree ; and that is no doubt found in the quicker or slower 
renewal of the atmosphere. This is confirmed by the fact that on many 
spots the fevers have become less after the forest has been cleared, or 
cut in a certain direction ; and this may explain why the miasmata cause 
little or no mischief in the swampy plains of the Madeira and Mamorc, 
Avhere the trosh breezes play- On the whole, it seems that the fevers are 
decreasing on the Madeira. 
ATuong the poorer eaoutchoiKt-collectors Peruvian bark is rarely 
found, though it has already come in large hide-covered bags from the 
