The doctor first showed us specimens of the various important snakes,
poisonous and non-poisonous, in alcohol. Then he showed us
preparations of the different kinds of venom and of the different
anti-venom serums, presenting us with some of the latter for our use
on the journey. He has been able to produce two distinct kinds of
anti-venom serum, one to neutralize the virulent poison of the
rattlesnake's bite, the other to neutralize the poison of the
different snakes of the lachecis genus. These poisons are somewhat
different and moreover there appear to be some differences between the
poisons of the different species of lachecis; in some cases the poison
is nearly colorless, and in others, as in that of the jararaca, whose
poison I saw, it is yellow.

But the vital difference is that between all these poisons of the pit-
vipers and the poisons of the colubrine snakes, such as the cobra and
the coral-snake. As yet the doctor has not been able to develop an
anti-venom serum which will neutralize the poison of these colubrine
snakes. Practically this is a matter of little consequence in Brazil,
for the Brazilian coral-snakes are dangerous only when mishandled by
some one whose bare skin is exposed to the bite. The numerous
accidents and fatalities continually occurring in Brazil are almost
always to be laid to the account of the several species of lachecis
and the single species of rattlesnake.

Finally, the doctor took us into his lecture-room to show us how he
conducted his experiments. The various snakes were in boxes, on one
side of the room, under the care of a skilful and impassive assistant,
who handled them with the cool and fearless caution of the doctor
himself. The poisonous ones were taken out by means of a long-handled