OBSERVATIONS AND CORRESPONDENCE. 



Life at High Altitudes and at Great Depths. 



[The following remarks have been suggested by Mr. Whymper's 

 conclusions recently noticed in our review of his work (pp. 219-220), 

 but Mr. Whymper has of course considered the question of the 

 experiences of aeronauts and dismissed them on account of the sudden- 

 ness of the alterations of pressure. — Ed.] 



Experienced hunters upon the Himalaya pursue game, without 

 feeling any appreciable inconvenience, at altitudes exceeding 20,000 

 feet above the surface of the sea, and balloonists have penetrated up 

 to 37,000 feet, or fully 7 miles above the sea's level. 



Mr. Glaisher in one of his balloon ascents remained in apparent 

 health up to 26,400 feet, or 5 miles, but, on arriving at 29,000 feet, 51 

 minutes after leaving land, he lost all muscular power, soon followed 

 by insensibility and fainting, possibly due to the glut or engorgement 

 of blood in the lungs from increasing insufficiency of oxygen, intensi- 

 fied by diminished skin-action in a dry temperature of 37° Fahrenheit 

 beloiv the freezing point of water. 



Hitherto high balloon ascents have been performed with such 

 speed that either 1,000 feet upwards or 4,000 feet downwards have 

 been readily accomplished in one minute, while in mountain 

 travelling an elevation of 1,500 feet is seldom completed within the 

 hour. 



Experiments indicate that by gradual ascents, long training, 

 frequent acclimatisation, and cautious diet, high altitudes above 

 30,000 feet (now considered by many fatal to man) are, with precaution 

 and practice, securely attainable. 



The air-hunger experienced by man at high altitudes occurs also 

 in fish when suddenly removed from a very low depth to the surface. 

 Thus, from the experiments of the " Challenger," it appears that fish 

 hooked at great depths often reach the surface in fragments, owing 

 to the disintegration of the tissues, caused by the enormous expan- 

 sion of the gases. In any case, the fish are dead and rigid, or the 

 stomach evaginated through the mouth ; considerable protruberance 

 of the eyeballs may also occur. It is very interesting to observe that 

 when nearing the surface the fish, owing to the expansion of its gases, 

 is literally shot through the water, and even projected above the 

 surface faster than the fisherman can draw in his line. 



J. Lawrence Hamilton, M.R.C.S. 

 30 Sussex Square, Brighton, 

 1st July, 1892. 



Sir, — I was struck by a retnark in Professor Lloyd Morgan's 

 masterly critique of the "Grammar of Science " in your last number. 



He says that " considering how enormously complex are the 

 influences which have conspired to bring about man as the crowning 



