444 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
The immunization lasts about a year, and toward the end enor- 
mous doses are given reaching 1 gram. The horse is then ready 
and the serum from its blood is antitoxic for the venom with which 
it has been inoculated. 
In such manner is prepared at Butantan the anticrotalic, the 
antibothropic and the polyvalent serums. The last is obtamed by 
alternating the injections, using the venom first from one kind, then 
from the other kind of snake, and, as its name indicates, it is valuable 
as a remedy for the bites of all Brazilian snakes. It is therefore of 
exceptional practical value. 
An immunized horse will furnish serum for a very long time, 
provided that from time to time new injections of the venom are 
administered. After each bleeding necessary for a supply of serum, 
the antitoxic power of the horse diminishes rapidly but recovers 
several days afterwards. 
In the case of man, the injection of the serum under the skin 
should be made during the 12 hours following a bite. If the kind 
of snake producing the bite is known, the serum specific to that kind 
is the more efficient toxin to employ in doses of from 10 to 20 ¢.c., 
for it works more quickly and with special efficacy. If the kind of 
snake is not known, as is usually the case, then the polyvalent 
serum must be injected in doses up to 60 ¢. ¢. in serious cases. 
The serum is furnished to the public in sealed tubes packed in 
little wooden boxes. A minimum price is charged. Further, the 
institute at Butantan distributes the serum free to hospitals, to 
cities, and to the very poor, together with injection syringes and the 
necessary directions for its use. The only remuneration asked by 
Dr. Brazil, at times, in exchange for the serum, is the snakes which 
are essential to him; and so by bringing a cascavel or a jararaca, the 
Brazilian countryman receives a tube of the liquid serum. 
I was very curious to visit the institution at Butantan during the 
few days I stopped at St. Paul near the outskirts of which it is 
situated. My distinguished colleague and friend, Dr. Alves de 
Lima, whom I can not thank too much for his generous hospitality, 
kindly offered to accompany me there. I copy the following account 
from the note book of my travels: 
A powerful 40-horsepower automobile carried us, raising clouds of dust, along the 
route which traversed a smiling country dotted with trees and exotic shrubs. After 
a ride of about half an hour we stopped at the gate of a kind of large chalet which 
belonged to a group of new buildings, the serotherapeutic institution of Butantan. 
A man of about 40 years of age, tall, energetic, sun burned, wearing a black mustache, 
with remarkably deep, black eyes, a reserved and deliberate manner in marked con- 
trast with his southern appearance, received us on the threshold. He wore a long 
white coat, such as surgeons and physiologists wear. Such was Dr. Vital Brazil, 
director of the institution and a great philanthropist. To him Brazil, and indeed 
all the other countries of South America, owe the systematic production of the serum 
