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 r = io~ 4 cm., we may put 



£ = 4X8o/io -4 = 3.2Xio 6 dynes/cm. 2 



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~ 4 cm. in 

 diameter to expand. 



e/Kat. 5 



~30cApr4 



ZqcMfjyi 



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 

 (a 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 tn 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 



m= 160 X io -6 g/day or 18 X io~ 10 g/sec. 



a relatively large value. 



