respiration carried on with 25 pupils during different school occupations. The most marked difference found was that between the standing and the sitting respiration. The decrease in total respiration for brief sitting (3 minutes) was about 8 per cent., and for longer periods (12 to 39 minutes), 50 per cent. Interesting differences appeared with different kinds of school work. Knitting, for example, showed an impeding effect upon the respiration of the upper left lung 18 per cent, greater than did reading aloud. In agreement with the results of Badaloni, the greatest impediment to respiration was found in the upper part of the lowered side of the chest. This in turn aggravates the asymmetrical condition and helps to explain why scoliosis tends to run a progressive course. Oker-Blom concludes that all kinds of school activities, including hand-work, must be frequently alternated with change of position and with physical exercises if the danger of scoliosis is to be avoided.
The School as a Cause of Morbidity
Hertel's pioneer study (7) of the health conditions and work habits of 3,141 boys and 1,211 girls in the secondary schools of Denmark not only revealed what was then regarded as an incredible amount of physical defectiveness, but also demonstrated sufficient correlation of morbidity with years of school attendance and with daily hours of study to forcibly suggest a cause and effect relation. In the first two classes (children eight to ten years) 18.4 per cent, were suffering from one or more chronic defects serious enough to impair health. By the end of the third year the amount had risen to 34 per cent., and by the end of the eighth year, with its average of 812 hours of daily study, to nearly 50 per cent. Especially significant is the fact that the pupils whose studies were chiefly of scientific nature showed a decidedly lower per cent, of morbidity than obtained among the students of classical courses, which make heavier demands upon strictly intellectual application and afford less opportunity for physical activity. Conditions were even worse among the girls, among whom morbidity rose rapidly from about 30 per cent, in the first two grades to over 60 per cent, by the age of 12 to 16 years. It is difficult to avoid the suspicion that the daily period of study, which increased concomitantly from about seven to about nine hours, may have been to some extent causally related to the increase in morbidity.
The later study of Schmid-Monnard (15) of 5,100 boys and 3,200 girls in the secondary schools of Germany confirmed essentially all the findings of Hertel, revealing in the upper grades a marked increase in frequency of headaches, insomnia and other nervous symptoms.
Roughly speaking, schools with both morning and afternoon sessions showed in the higher grades nearly twice as much morbidity as
