 He hoped to find the yellow fever microbe that had been reported by Dr. Domingos José Freire of the Rio de Janeiro faculty of medicine.He reached Havana in November 1887, but was unable to find the micro-organisms in the blood of victims that had been reported by Freire.Gibier did find a bacillus in the intestine of a victim that seemed a possible cause of the disease, but further tests did not confirm this.