278 Lifv and Letters of Francis Oaltoii 



unifurniity in siicccsaivo experiments when the pupils are fresli; irrttgulurity and prevalent 

 dcUv whi-n tliey are tinnl. I wish tliat tt^chors would often try this Miinple, aiiiusinfr, and 

 •ttriiotivo experiment, and when they have assured tiiemselves that their class enters into its 

 performance with interest and curiosity, they niiglit \n^'^\n to make careful records at different 



rriods of the day and see whether it admits of Iwing uwhI as a t^'st of incipient fatigue, 

 should l>e exceedingly gWl to receive accounts of their ex|iericncc8. Deception must of 

 course be guarded against." (p. 160.) 



I have not so far come across any data in the GaltoyiitDui. \\\\'\c\\ .sui^'cro.st 

 that any experiences were communicated to Galton. 



From the teachers' replies Galton in the memoir draws two iiinclu.sion.s: 

 The first snggasts the reiuson why mental fatigue leaves effects so nmch 

 more serious than Ixxlily fatigue. When a man is fatigued in hody he has 

 many of the same symptoms as arise in mental fatigue, out 



"as soon as the Ixxlily exertion has c1os<hI for the day, the man lies down and his muscles 

 have rest; hut when the mentiilly fatigued man lies down, iiis enemy coiitinues to harass him 

 during his weary hours of sleeplessness. He cannot quiet his thoughts and ho wastes himself 

 in a futile way." (p. 166.) 



I am not clear that this diagnosis is of universal truth, especially in the 

 case of men not habitually used to excessive work. Over physical exertion — 

 a fifty-mile walk, or a very strenuous bicycle ride, or a whole day of heavy 

 gardening work — may l)e followed by muscular fidgets, by tinrestrainal)le fits 

 of shivenng, and by actual mental excitement which renders .sleep or muscle 

 rest imjxi.ssilile, and the effects may be felt for days afterwards. It says 

 mucli for Galton's constitution that no exj)erience of this kind .seems to have 

 sugge.sted to hira that for some individuals bodily and mental fatigue run 

 much the s,'\me course'. 



The .second conclusion that Galton reaches is that breakdowns usually 

 occur among those who work by themselves, and not among pupils whose 

 teachers keep a reasonable ovensight. Too zeah)us pupils are rare. The 

 chief danger occurs when 



"young persons are qualifying themselves for the profession of a tciicher, and have also t<> 

 support theniselv(>s antl p«'rhaps to endure domestic trials at the same time. Dull p«(rsr)ns 

 proti-ct their own health of brain hy refusing to overwork. It is among those who are 7.eal<>us 

 and eager, who h.'ive high aims and idea-s, who know themselves to Ix; mentally gifted, and are 

 too generous to think much of their own health, that the most fre<]uent victims of overwork 

 are chie6y found." (p. 166.) 



There is much in this paper on Mental Fatigue which is of high sug- 

 gestivene-ss, and it shovdd certainly be read by any one j)lanning a more 

 elaborate statistical iiujuiry into a subject still far from completely ex- 

 plored. The recent discovery and di.scussion of shell-shock show how large a 

 section of a modern poj)ulation^ — and not the least intelligent and zeixlous — 

 beai-s the terrible loud of inherited neuroses. One of the points not touched 

 on in Galton's questionnaire is the family history of those who have suffered 

 serious j^rostration from mental overworlv. We should not be surprised to 

 find a link between this CJitegory and that of the shell -shocked. In the 



' It would be of much interest to inquire into the extent to which nervous breakdowns 

 can bo directly traced to over strenuous physical exertion. 



