Page:The Algebra of Mohammed Ben Musa (1831).djvu/194

 especially to cure a fractured bone. It is thus used in the following passage from Al-Mutanabbi (p. 143, 144, ed. Calcutt.) “O thou on whom I rely in whatever I hope, with whom I seek refuge from all that I dread; whose bounteous hand seems to me like the sea, as thy gifts are like its pearls: pity the youthfulness of one, whose prime has been wasted by the hand of adversity, and whose bloom has been stifled in the prison. Men will not heal a bone which thou hast broken, nor will they break one which thou hast healed.”

Hence the Spanish and Portuguese expression algebrista for a person who heals fractures, or sets right a dislocated limb.

In mathematical language, the verb means, to make perfect, or to complete any quantity that is incomplete or liable to a diminution; i.e. when applied to equations, to transpose negative quantities to the opposite side by changing their signs. The negative quantity thus removed is construed with the particle ب: thus, if $$x^2-6=23$$ shall be changed into $$x^2=29 $$, the direction is اجبر المال بالستة وزدها على الثلثة والعشرين i.e. literally “Restore the square from (the deficiency occasioned to it by) the six, and add these to the twenty-three.”