ReviewsBr Med J 1931; 2 doi: https://doi.org/10.1136/bmj.2.3678.18 (Published 04 July 1931) Cite this as: Br Med J 1931;2:18
Log in using your username and password
Log in through your institution
Register for a free trial to thebmj.com to receive unlimited access to all content on thebmj.com for 14 days.
Sign up for a free trial