71 THE AM.\ZON AND MADEIHA RIVEKS. 
Tlicre, ill spite of its numerous uiid sliurp bciuls, tlie river is uuviguljlc 
by steamers of feet draught, as it has an average depth ot 5 feet, 
a width of from 270 to 330 yards, aud a rapidity of from 1 foot 
to Ij feet per second. As most of oim canoes were anything hut 
water-tight after their three months’ hard work, and especially after 
their repeated draggings on land over stocks and stones, we resolved 
to caulk them before we proceeded fiu'ther. The Castanheira (^Bar- 
tholleiia exceka\ whose fruit is knouTi in Europe xmder the name ot 
Bruuil nuts, supplied xis with the reqxured material; and, as there xvas 
pleixty of these gigantic trees rising tall aud straight as columns, our 
Mojos had little trouble to collect a sxxfBcient qxxantity of their bark. 
Tlicy fii’st made with an axe two horizoutal ixxcisions at an iutcirval of 
7 feet froxxx each other, and then with xvoodeu wedges loosened a 
strip of bark of about feet breadth. With coutinxxcd beating the 
outer hark is separated froxn the bast, and the latter is reduced to 
a bundle of soft fibres, which, after being washed and dried in the 
sxiu, are fit for use. While so employed, one of oxxr paddlers was stung 
in the hand by a poisonous ant (Tucandeira) of nearly an inch and a half 
long, and in a short time his haxid and arm were sxvollen up to the 
shoxxlder. As I treated him successfully with salmiak, one of the 
Bolivians told ixxe that in his country the xxse of balms similar to those 
of the Soxxth African poison-doctors, in sxxch cases, was quite common. 
He had himself witnessed their efficacy in the case of an Indian woxxndcd 
by the poisonous sting of a ray. What nxay be considered the healing 
principle in these antidotes I cannot tell — dicant Paduani ! — I limit 
myself to recording the fact. 
In such urgent cases it is only natxxral that people should invent 
all sorts of cxtraordixiary chmgs in coxxntries where there are neither 
physicians nor apothecaries’ shops. Once, in the province of Minas, 
while opening a picada through a piece of dense virgin-forest with a 
lew negroes, a fine hunting-dog belonging to a neighboxxring plaixter, 
which had followed me and had afterwards been hunting upon his own 
account, came suddenly up with hanging ears and tail, and xx’-hining 
piteously. On inspection, we foxmd a tumour with two small red points 
on his neck, swellixxg almost visibly, xvhich the negroes one and all 
declared to be the bite of a poisonous snake. As nothing else xva.s 
at hand, a piece of very strong fumo dc Mmas (Minas tobacco) was 
steeped in water; the xvouud was washed with some of it, aud the 
