260 SCIENCE FROM AN EASY CHAIR 



without injury, and, indeed, with great benefit in some 

 serious conditions of collapse. Dr. Leonard Hill, F.R.S., 

 of the London Hospital Medical College, has, however, 

 recently shown that oxygen gas, of 97 per cent, purity, 

 may be breathed continuously for as much as two hours 

 without any ill-effects or sense of inconvenience. 

 Contrary to what has been stated, it is neither exciting 

 nor unpleasant. He has made the experiment on 

 himself and on some of his assistants, and in doing so 

 has made use of such an apparatus as that above- 

 mentioned so as to ensure the in-take of undiluted 

 oxygen. 



Dr. Hill and Mr. Martin Flack have further found that 

 the exhaustion and labouring of the heart which is 

 brought on by such special exertion as that involved in 

 running a hundred yards race or a quarter-mile race, is 

 almost completely avoided if the runner "fills his lungs" 

 with oxygen gas before starting. The runner takes the 

 oxygen gas into the lungs for some two or three minutes 

 before starting to race ; of course, the lungs are not 

 thus actually "filled" with oxygen, but a much larger 

 proportion of that gas is lodged in them than when 

 ordinary air is breathed, and a full supply is thus afforded 

 to the blood. The " distress " caused by violent athletic 

 efforts appears to be entirely due to the using up of the 

 available oxygen by the unusual activity of the muscles. 

 The heart itself suffers most, the breathing becomes 

 laboured, and there is a sense of suffocation, due simply 

 to the urgent demand by the blood, heart and muscles 

 for more oxygen. If, therefore, we ensure that there is 

 an extra supply of pure oxygen in the lungs before 

 the unusual effort is made, we avert these distressing 

 symptoms : the unusual quantity of oxygen needed is 

 ready for use. Dr. Hill himself and young men who 

 have tried the plan of inspiration of oxygen before a 





