426 THE POPULAR SCIENCE MONTHLY. 



of a given drug produces on no two persons exactly like sets of effects, 

 and produces even on the same person different effects in different con- 

 stitutional states, we see at once how involved is the combination of 

 factors by which the changes in an organism are brought about, and 

 how extremely contingent, therefore, is each particular change. And 

 we need but watch what happens after an injury, say of the foot, to 

 perceive how, if permanent, it alters the gait, alters the adjustment 

 and bend of the body, alters the movements of the arms, alters the 

 features into some contracted form accompanying pain or incon- 

 venience. Indeed, through the readjustments, muscular, nervous, and 

 visceral, which it entails, this local damage acts and reacts on function 

 and structure throughout the whole body, producing effects which, as 

 they diffuse, complicate incalculably. 



While, in multitudinous ways, the Science of Life thrusts on the 

 attention of the student the cardinal notions of continuity, and com- 

 plexity, and contingency, of causation, it introduces him to a further 

 conception of moment, which the inorganic Concrete Sciences do not 

 furnish the conception of what we may call fructifying causation. 

 For, as it is a distinction between living and not-living bodies that the 

 first propagate while the second do not, it is also a distinction be- 

 tween them that certain actions which go on in the first are cumula- 

 tive, instead of being, as in the second, dissipative. Not only do or- 

 ganisms as wholes reproduce, and so from small beginnings are capable, 

 by multiplication, of reaching great results ; but components of them, 

 normal and morbid, do the like. Thus a minute portion of a virus, in- 

 troduced into an organism, does not work an effect proportionate to 

 its amount, as would an inorganic agent on an inorganic mass ; but, by 

 appropriating materials from the blood of the organism, and thus im- 

 mensely increasing, it works effects altogether out of proportion to its 

 amount as originally introduced effects which may continue with ac- 

 cumulating power throughout the remaining life of the organism. It 

 is so with internally-evolved agencies as well as with externally-in- 

 vading agencies. A portion of germinal matter, itself microscopic, 

 may convey from a parent some constitutional peculiarity that is in- 

 finitesimal in relation even to its minute bulk ; and from this there 

 may arise, fifty years afterward, gout or insanity in the resulting 

 man : after this great lapse of time, slowly-increasing actions and 

 products show themselves in large derangements of function and 

 structure. And this is a trait characteristic of organic phenomena. 

 While, from the destructive changes going on throughout the tissues 

 of living bodies, there is a continual production of effects which lose 

 themselves by subdivision, as do the effects of inorganic forces, there 

 arise from those constructive changes going on in them, by which 

 living bodies are distinguished from not-living bodies, certain classes 

 of effects which increase as they diffuse go on augmenting in volume 

 as well as in variety. 



