I need hardly say that in the following pages I have not attempted a scientific memoir. My object has been to supply that part of my husband's life the material for which would not be within the reach of another biographer.

The selection from his letters might have been much larger, if I could in all cases have inserted those of his correspondents. Without these many would have been incomprehensible. As it is, I may have over-estimated the attention which readers will be disposed to give to them. My rule in choosing the letters has been to take those which are most characteristic of the writer, and in this way to give to readers already acquainted with him through his writings a more familiar knowledge of him as a man.

His connection with University College, and the events which led to his leaving it, are necessarily made prominent. So long a time has elapsed since their occurrence, and I have known so little during that time of the Institution, that I cannot even surmise how the present Council would in like circumstances share the convictions or conform the action of its predecessors. After the lapse of sixteen years I trust that the narrative will provoke no revival of the somewhat acrimonious controversy which ensued. It might perhaps have been in some ways better that Mr. De Morgan should have published a fuller statement of his views at the time, and have thus left less to be done by his biographer.