By the early 1960s his health had deteriorated to such an extent that he could stand in front of the blackboard for only a few minutes before he had to sit down and rest.
Sa pamamagitan ng unang bahagi ng 1960 s kanyang kalusugan had deteryorado na tulad ng isang lawak na siya ay tumayo sa harap ng pisara para sa mga lamang ng ilang minuto bago niya sa umupo at magpahinga.