1893.) The Quantity of Human Life. 199 
innumerable vicissitudes both accidental and periodic. While 
there is an endless influx of disturbing forces which augment 
or deplete the quantity of life at all times, yet there are cer- 
tain periodic causes which promote recurrence of cycles of 
consciousness. Such are the alterations of day and night, the 
recurrence of the seasons, and the widely extended observance 
of days and customs. How much the quantity of life is tem- 
porarily augmented by the convivialities of Christmas and 
other commemoration days! Then there is a diurnal rise and 
fall in the conscious life. The morning with its vivid and 
buoyant sensations; the rising of the energies and their tem- 
porary lull at midday, and their slow descent with the 
descending of the sun. Then the twilight comes on with its 
calm reflections and feelings, succeeded by the serenity of 
sleep. But even here the pulse of consciousness rises and falls, 
summoned into being by the vague apparitions and muffled 
ounds of dreams. At length these increase in vividness 
and frequency, the pulse of consciousness grows more intense 
until we are again ushered into the hazy realities of another 
morning. Then there are the periodicities arising from the 
changing seasons. 
To one who dwells during a period of years in the same 
place, the events which are repeated from year to year are 
much in excess of those which are variable. Hence the 
annual rhythms of consciousness are quite well marked. The 
conscious life throughout the time of its existence is subject to 
quite well defined periods of change. There are several strik- 
ing analogies between the consciousness of infancy and that 
of extreme old age. Both are oblivious of details, apprehend- 
ing only to the salient outlines and strong qualities of things. 
Both repeat and re-repeat simple things, the babe its lullaby, 
the old man his favorite story. The consciousness of old age 
is reminiscent because the powers are feeble, and reminiscences 
are paths of least resistance. Quite otherwise is the consciousness 
of youth and the prime of life. It is vigilant and aggressive, 
and ever seeking new combinations of experience. Not only 
is the quantity of the conscious life extremely varied in its 
different periods of development, but also in its quality. In 
