y. B. S. Haldane 113 



fifty, there was no corresponding rise in pressure in the neck 

 and arm vessels. In other words, the healthy heart was able 

 to nullify the effect of gravity. 



There is no special risk in hanging upside down for 

 three minutes — nothing more is involved than a certain 

 amount of discomfort. The sleepless tests which were 

 conducted in Washington in 1925 must have imposed 

 a more severe strain upon the students who carried 

 them out. Eight undergraduates volunteered. Six com- 

 pleted sixty hours without sleep and two completed 

 eighty-five. The object was to test the change in mental 

 and physical condition caused by lack of sleep. 



Every week there are similar instances of self-sacrifice 

 in the interests of Science, but as a rule we hear nothing 

 about them. They pre taken as a matter of course by 

 scientists of all nations, and even when news of some 

 desperate experiment leaks out the names of the experi- 

 menters are usually concealed. It is known, for instance, 

 that several British laboratory workers inoculated each 

 other with living cancer germs in order to test the 

 theories of Doctors Gye and Barnard, but the names of 

 these astonishingly brave men were never made public. 



Amateur as well as professional scientists have shown 

 immense courage in their work. Mr Haldane mentions 

 one of these in a paper called Scientific Research for 

 Amateurs. He describes the swim of the young French- 

 man Norbert Carteret through the cavern of Montespan. 

 Here was a stream flowing out through a cave in which 

 had already been found traces of a long-vanished race. 

 Flint tools and bones had been discovered, and it oc- 

 curred to Carteret that if he could force his way up this 

 stream he might make important finds. Carrying matches 

 and candles in a waterproof case, he waded up the swift, 

 ice-cold river to the spot where the roof met the water ; 

 then after taking a long breath he dived and swam 



