So that it is in truth , of operation upon a man ' s mind , of like virtue as the alchemists use to attribute to their stone , for man ' s body ; that it worketh all contrary effects , but still to the good and benefit of nature 所以就实际的作用而言,友谊之于人心其价值真有如炼金术士常常所说的他们底宝石之于人身一样;这宝石,依术土们底话,是能产生种种互相反对的效力,然而总是有利于天禀的。