LIQUIDS AND ALUED EXPERIMENTS. 



27 



which the bubbles are initially expanded. In fact, if the pressure within 

 be taken as p = \T/r, where T is the surface tension and r the radius of the 

 sphere, if the bubbles grow almost from the order of microscopic dimensions, 

 say from ;•= io~^ cm., we may put 



/> = 4X8o/io~'* = 3.2Xio^ dynes/cm.^ 



Thus the initial pressure would have to be of the order of several atmos- 

 pheres, if this explanation is correct. As not more than one atmosphere 

 is available, the original air-bubbles should be larger than 6Xio~^ cm. in 

 diameter to expand. 



Ji(a\ 



Fig. 8. — Chart showing loss of mass of gas in diver in lapse of days. 

 Diffusion of air into hydrogen. 



Between March 9 and 16 the rate has somewhat abruptly decreased 

 (o to b in curve). 



Between March 16 and 30 the weight of the imprisoned air was nearly 

 stationary {b to c in curve), a condition of things which has again been 

 reached abruptly. Hence the per second influx of hydrogen and the efflux 

 of air are here about equal, remembering, however, that m is not the actual 

 mass. 



From March 20 the pronounced efflux suddenly begins, at a specific 

 though slowly increasing rate until April 30 {cde in curve) . It would seem 

 to be probable that during this interval the content of the swimmer is 

 largely hydrogen ; and yet the apparent mass rate of efflux is 



-10 



m = 160X10 g/day or 18X10 g/sec. 



a relatively large value. 



