INFLUENCE OF THE BLOOD ON THE BRAIN. 215 



case more time is required to re-establish the ex- 

 hausted powers of the brain. A good deal of ob- 

 servation has convinced me, that -the transmission 

 of imperfectly oxygenated blood to the brain is 

 greatly more influential in the production of nervous 

 disease and delicacy of constitution than is com- 

 monly imagined ; and I am delighted to see the same 

 truth so powerfully insisted on by Mr. Thackrah 

 from extensive experience in the manufacturing dis- 

 trict about Leeds. Having, however, dwelt on this 

 subject in the preceding chapter, 1 need not repeat 

 the observations already made.* 



Although, in delicate constitutions, the health of 

 the brain and nervous system is often impaired by 

 inadequate nutrition, and a sufficient supply of nour- 

 ishing food is therefore indispensable to their well- 

 being, yet, as this condition is implied in the pre- 

 ceding, and its separate consideration would lead 

 us too far from our main object, I shall not dwell 

 upon it here. I shall merely state, that starvation 

 often affects the brain so much as to produce fero- 

 cious delirium, and that, in the Milanese, a species 

 of insanity arising from defective nourishment is 

 very prevalent, and is easily cured by the nourishing 

 diet provided in the hospitals to which the patients 

 are sent. I have, seen the mental functions weak- 

 ened, and the brain disordered, by the same cause 

 inadequate nutrition at the period of rapid growth. 

 This defective nutrition, however, it must be ob- 

 served, does not always depend on want of proper 



* An intelligent teacher in Edinburgh, to whom I coramuni 

 cated the above views, and who immediately set about acting 

 On them by turning his pupils out to play, and.throwing open the 

 door and windows for ten minutes at the end of the first hour's 

 confinement, assures me that the difference between the languor 

 and little power of sustained attention exhibited under the old 

 system, and the activity shown under the new, is very marked, 

 and that the interval of relaxation is most profitably spent time 

 both to his pupils and himself, as they return to work with 

 tew life. 



