viii PREFACE 



the sense are prone to pass away together and leave no 

 trace upon memory. Not upon conscious memory, at 

 least ; for it is believed that every experience sets an 

 impression, indelible except by disease, upon the 

 almost incalculably delicate machinery of reminiscence, 

 and that such impression may be revived at will, pro- 

 vided the intelligence has not lost record of the 

 precise tissue or ganglion in which it is stored. Some 

 memories we constantly recall without conscious 

 effort, familiarity rendering them easy of access ; others, 

 deeply overlaid by later experience, have to be pain- 

 fully sought for, or lie dormant till some chance a 

 sentence spoken or a passage read drives the blood 

 along the delicate capillaries about their hiding-place. 

 ' Curious that I never remembered that till now,' you 

 ejaculate, as some long forgotten scene or passage leaps 

 to light, its outlines, even its details, scarcely dimmed 

 by long immurement. 



Impressions of happiness or enjoyment seem to be 

 more transient than those of distress or suffering. Few 

 spirits are of such fibre that they can bear the legend 

 of the sundial Horas non numero nisi serenas ; yet 

 many a weary or anxious mind would derive refresh- 

 ment from reflection upon the moments when it was 

 agreeably employed upon small matters, did it but 

 possess an easy clue through the labyrinth of retrospect. 

 There is no such simple clue as written notes, not in 



