 In order to learn research bacteriology, Álvarez went — at his own expense — for six months of intensive study at Johns Hopkins University.On his return, he developed a method for the better diagnosis of macular leprosy.With a small mouse-tooth forceps he would lift up a little piece of skin, snip it off with scissors, grind it into a fluid in a small glass mortar, and then stain the fluid for Hansen's bacilli.