Chapter XIV: Concerning unnatural causes of Sleep and Waking.

Chapter XVII: Of causes of long and short sleep.


APPENDIX D
QUESTIONNAIRE ON SLEEP

In order to get the facts about Sleep we sent a question sheet to a large number of persons selected by classes. We began with a thousand professors in order to get suggestions which might make the investigation more useful. The following request was sent out:

Please Fill Out and Return—

We shall be glad to supply additional copies of this slip upon request—we desire the largest number of replies possible and it is hoped the scientific interest of the subject will lead you to aid us in procuring them.

No scientifically complete tabulation and study of data has yet been made on Sleep.