Consider, then, how great must be the damage inflicted by undue mental excitement on children and youths.  More or less of this constitutional disturbance will inevitably follow an exertion of brain beyond the normal amount; and when not so excessive as to produce absolute illness, is sure to entail a slowly accumulating degeneracy of physique.  With a small and fastidious appetite, an imperfect digestion, and an enfeebled circulation, how can the developing body flourish?  The due performance of every vital process depends on an adequate supply of good blood.  Without enough good blood, no gland can secrete properly, no viscus can fully discharge its office.  Without enough good blood, no nerve, muscle, membrane, or other tissue can be efficiently repaired.  Without enough good blood, growth will neither be sound nor sufficient.  Judge, then, how bad must be the consequences when to a growing body the weakened stomach supplies blood that is deficient in quantity and poor in quality; while the debilitated heart propels this poor and scanty blood with unnatural slowness.

And if, as all who investigate the matter must admit, physical degeneracy is a consequence of excessive study, how grave is the condemnation to be passed on this cramming-system above exemplified.  It is a terrible mistake, from whatever point of view regarded.  It is a mistake in so far as the mere acquirement of knowledge is concerned.  For the mind, like the body, cannot assimilate beyond a certain rate; and if you ply it with facts faster than it can assimilate them, they are soon rejected again:  instead of being built into the intellectual fabric, they fall out of recollection after the passing of the examination for which they were got up.  It is a mistake, too, because it tends to make study distasteful.  Either through the painful associations produced by ceaseless mental toil, or through the abnormal state of brain it leaves behind, it often generates an aversion to books; and, instead of that subsequent self-culture induced by rational education, there comes continued retrogression.  It is a mistake, also, inasmuch as it assumes that the acquisition of knowledge is everything; and forgets that a much more important thing is the organisation of knowledge, for which time and spontaneous thinking are requisite.  As Humboldt remarks respecting the progress of intelligence in general, that “the interpretation of Nature is obscured when the description languishes under too great an accumulation of insulated facts;” so, it may be remarked respecting the progress of individual intelligence, that the mind is over-burdened and hampered by an excess of ill-digested information.  It is not the knowledge stored up as intellectual fat which is of value; but that which is turned into intellectual muscle.  The mistake goes still deeper however.  Even were the system good as producing intellectual efficiency, which it is not, it would still be bad, because, as we have shown, it is fatal to that vigour