390 



SCIENCE PROGRESS 



The method of stage decompression was very thoroughly 

 tested on goats, and compared with the old method of uniform 

 decompression. The result was to show, we think, beyond all 

 question that the stage decompression method is greatly superior, 

 particularly for diving work. Even when the rate of decom- 

 pression was much too fast by either method, stage decompression 

 proved considerably safer. The accompanying table (Table VI.) 

 shows a number of results obtained with the same animals and 

 under the same conditions, except that the method of decom- 

 pression was varied. It should be remarked that in each 

 series, excepting C, the rate of stage decompression was less 

 slow than what was calculated to be required for goats in order to 

 prevent all symptoms, and considerably so in series B, D, and E. 

 The occurrence of a few slight symptoms was therefore expected. 

 It will be seen, however, that deaths and severe symptoms were 

 entirely eliminated by the stage decompression, whereas a 

 number of cases occurred with uniform decompression in the 

 same time, besides a much greater number of slight cases. 



TABLE VI 

 Absolute Pressure 6 Atmospheres 



With goats we found it necessary to provide for parts of 

 the body taking as much as forty-five minutes to become half- 

 saturated or half-desaturated with a given alteration of pressure. 

 For man we therefore considered it necessary to provide for 

 parts requiring seventy-five minutes, as the respiratory exchange 

 per unit of body weight in man is three-fifths that of goats. 



1 Paralysis of foot lasting 1 hour. 



2 3 cases of paraplegia, 4 of temporary paralysis, 2 of dyspnoea, and 2 of 

 undefined illness. 



