Instituto Butantan and production of sera. The Instituto Butantan also operate the "Hospital Vital Brazil", a specialist hospital that offers free treatment for poisonous animal stings and bites. The institute also accepts donations of serpents, arthropods and other animals captured by the public and by a network of collaborating centers and individuals. The following research laboratories are part of the Butantan Institute: Important Brazilian scientists who have worked in the Butantan Institute are: Vital Brazil, Afrânio Pompílio Gastos do Amaral, Isaias Raw, Samuel Pessoa, Willy Beçak. The Institute has strong collaborative ties with the Pasteur Institute, Paris, France, and with the Oswaldo
Oswaldo Cruz existed since 1837 but had never been put into practice. Therefore, on June 9, 1904, following a proposal by Oswaldo Cruz, the government presented a bill to the Congress requesting the reestablishment of obligatory smallpox vaccination. The extremely rigid and severe provisions of this instrument terrified the people. Popular opposition against Cruz increased sharply and opposition newspapers started a violent campaign against this and the federal government in general. Members of the parliament and labor unions protested. An anti-vaccination league was organized. On November 10, the Vaccine Revolt exploded in Rio. Violent confrontations with the police ensued, with strikes, barricades,