His teaching at the university was interrupted in 1938, the year the Italian Government approved the " Racial Laws ", "unreasonable, before being unjust". Forced by the law to an early retirement, the Council of the faculty of engineering substituted him with Graffi: he was very happy with the council choice, due to their friendship and mutual esteem. For his part Graffi, who could not adopt Foà's handouts due to prohibition imposed by the laws on publications by Jewish authors, published them under his name: cautiously, he kept sending to Foà's house students for private lessons, in order to help him supplement his small retirement pension.