448 OLD ALPINE JOTTINGS. 



work, but our first care was to dissipate the wrecked 

 tissues of our bodies, and to supply their place by new 

 material. 



Twenty-four years ago Mayer, of Heilbronn, with 

 that power of genius which breathes large meanings 

 into scanty facts, pointed out that the blood was * the 

 oil of life,' and that muscular effort was, in the main, 

 supported by the combustion of this oil. The recent re- 

 searchesxrf eminent men prove the soundness of Mayer's 

 induction. The muscles are the machinery by which the 

 power of the food is brought into action. Nevertheless, 

 the whole body, though more slowly than the blood, 

 wastes also. How is the sense of personal identity 

 maintained across this flight of molecules? As far as 

 my experience goes, matter is necessary to conscious- 

 ness, but the matter of any period may be all changed, 

 while consciousness exhibits no solution of continuity. 

 The oxygen that departs seems to whisper its secret 

 to the oxygen that arrives, and thus, while the Non- 

 ego shifts and changes, the Ego remains intact. Con- 

 stancy of form in the grouping of the molecules, and 

 not constancy of the molecules themselves, is the corre- 

 lative of this constancy of perception. Life is a wave 

 which in no two consecutive moments of its existence 

 is composed of the same particles. 



The ancient lake-beds of the Alps bear directly upon 

 those theories of erosion and convulsion which, in 1864, 

 were subjects of geologic discussion. They are to be 

 found in almost every Alpine valley, each consisting of 

 a level plain formed by sediment, with a barrier below 

 it, which once constituted the dam of the lake. These 

 barriers are now cut through, a river in each case flow- 

 ing through the gap. How cut through ? was one of 

 the problems afloat five or six years ago. Some supposed 



